1
I. DESCRIPTION OF THE COMPANY TAI, Turkish Aerospace Industries Inc., or the full title TUSAS Aerospace Industries is a Turkish American joint venture company established in May 1984. TAI’s shareholders can be summarized as follows: 49 % Turkish Aircraft Industries, Inc. 1.9 % Turkish Air Force Foundation 0.1 % Turkish Air League
42 % General Dynamics of Turkey 7 % General Electric Thecnical Services Company, Inc.
with a total investment of $ 292,000,000 . TAI is located on the 35th kilometer of the Ankara Istanbul motorway .The industrial facility buildings under roof covers an area of 130,000 square meters. Only five years after its establishment, TAI has constructed a modern and complete aircraft facility comparable to most aerospace companies in the world . The total number of employees in TAI is 2,300 out of which 40 % are university graduates. Experienced and qualified personnel are an absolute necessity, so 347 key personnel have been trained at General Dynamics Fort Worth facilities. Remaining employees have been trained from 3 to 12 months in special fields of aerospace technology . A broad view of ‘ TAI MANAGEMENT ORGANIZATION ‘ can be found in appendix 1 . The main objective in establishing TAI is to meet the modern aircraft requirement of the Turkish Air Force through domestic production and lay the foundation for the Turkish Aerospace Industries .TAI ’s first big step is to produce and fly out F-16 aircraft. Starting from zero, TAI, was successful to produce the F-16 FIGHTING FALCON, a product of most sophisticated aerospace in the world in a short period of time, such as two years. The assembly of the first F-16 was started on two February 1987 and it was completed successfully and delivered to the Turkish Air Force on 30 November 1987. TAI has produced the seventh “ PERFECT “ F-16 among over 2600 aircraft produced by General Dynamics and its components up to now. Produced seven zero defect aircraft out of its total production up to 1990.
2
Apart from F-16 program, a light transport aircraft program is going on which is CASA CN-235M. Production of CN-235M began with final assembly and gradually passed into manufacturing phases .TAI is producing 92 % of the total airframe .26 of the 50 CN-235M is produced. TAI has also produced and delivered 34 SF- 260 trainers to the Turkish Air Force under a subcontract with AGUSTA of Italy. TAI is also operating some projects. One of them is the Unmanned Air Vehicle (UAV). Planning and production of two prototypes are completed successfully. Improvement studies are still going on. HD-19 ,a two purpose aircraft that can be used either as a light transport aircraft or as a passenger plane, is another project that TAI is working on.
II. INTRODUCTION There is no doubt that engineering has a great role on the development of technology. All the theoretical knowledge that were found and improved by the scientists
3
come to scene with the engineering applications. As the scientists and engineers go on studying and investigating, new foundations will come out, and the technology will further develop. Practical experience is of the same importance as the theoretical knowledge for engineers, and summer practice is a good way of improving the practical experience. We, as mechanical engineering candidates, are able to see not only the production techniques and the stuff thought in the school, but also the flow of operations in the real life. The problems that arise in real engineering applications are much more complex. A very tiny mistake can cause waste of time, material and money in great deals. TAI is a perfect place to see how serious an engineer must do his job, because the product is an aircraft which takes millions of dollars, and many hours to manufacture. This summer practice was also useful to understand the knowledge better that is taught in ME202 Principles of Production Engineering, ME113 & ME114 Engineering Drawing, MetE227 & MetE228 Engineering Materials courses. We were able to see the materials used, the production techniques, the equipment used in production, and many other applications. It was very impressing to follow the operation sequence of a part starting from raw material and finishing as a product. All the processes in aircraft manufacturing, the equipment used with their technical qualifications are handled in the main text of the report. There is also brief explanations of some processes and some machines in the main text.
III. MAIN TEXT OF THE REPORT 1. Nature of operations : It is better to understand the sequence of operations and the flow of work in TAI before explaining the production techniques and the machines used.
4
The manufacturing system operating in TAI is neither a job shop nor a mass production system but we can name it as a to - order system that is strictly dependent on contractual specifications. But using general purpose machines rather than more specialized, dedicated equipment is a big resemblance between job shop and to-order systems .The main characteristics of the system are : i. General purpose machines are used , ii. Highly skilled people are needed , iii. Material handling is manual in the same task center . The customer specifications and production quantity are clearly defined with details in the contract. By producing an F-16, 75,000 parts and 8000 tools are involved. A SOIR ( Shop order and inspection report ), is released by the Planning Department. SOIR is a package which contains all the information about the part to be manufactured such as the technical drawing of the part called blue-print, and the manufacturing instructions.
TAI Organization Scheme : Tooling & Fabrication Machining Conventional Machining NC Machining
Sheet Metal Fabrication & Machining Sheet Metal Fabrication Chemical & Metallurgical Processes
Tool Design & Manufacturing
CAMB
Tool Engineering
Composite
Tool Manuf. & Machining
Bonding
Plastic Tool Fabrication Tubing & Welding
2. Raw Material :
Tool Planning
Raw material is the main input of detail parts manufactured .Tube extrusions, bars, rods, sheets and plates are the basic structures used in TAI as raw material. Various alloys with different qualifications are used in production. These are : Aluminum Steel Others
78.3 % 10.5 % 6.9 %
Graphite - Epoxy Titanium
2.7 % 1.6 %
5
Aluminum is the most important of the nonferrous metals for its unique and attractive properties. Its workability, light weight, corrosion resistance, and its high electrical and thermal conductivity make it very useful especially for aerospace production. A special alloy of aluminum is used which is coming from U.S.A to TAI. Material management activities in TAI is performed by about 100 employees majority of whom have undergone training at General Dynamics Fort Worth on the most sophisticated material management systems. Material management operations are supported by the most advanced computer systems.
3. Tooling and Fabrication : TAI fabrication has a very extensive potential in producing detail parts for all types of air vehicles at a high technology and chain production level capabilities in : CONVENTIONAL MACHINING COMPUTER NUMERICAL CONTROL MACHINING SHEET METAL FABRICATION TUBING AND WELDING CHEMICAL AND METALLURGICAL PROCESSING COMPOSITE & METAL BONDING (CAMB) and it furthermore has the following tooling capabilities such as : tool design and manufacturing, jigs and fixtures, plaster patterns, fiberglass tooling, form block, foundry and die finishing .
3.1. Conventional machining : Metal cutting, commonly called machining, is the removal of the unwanted metal from a workpiece in the form of chips so as to obtain a finished product of desired size, size, shape, and finish. TAI conventional machining area consists of four work-shops where all kinds of conventional machining operations of various parts with complex features are performed, both for tooling and fabrication purposes. Existing equipment and machine tools are up to modern standards and through which ; highly accurate tolerances, even for large volumes of production as well as precision works of more universal nature, are maintained.
6
The existing work-shops are : First cutting Turning Milling Grinding Tool & Cutter Grinding Drilling & Boring CNC Machining
3.1.1 First cutting : Raw material, after being tested if it suits the required specifications or not, come to the first cutting area to be given a rough size. The specifications being the material, form (plate, rod, tube etc.), hardness, and conductivity are tested also in the first cut area. Sawing, cross-cutting, oxy-plasma/flame cutting, shearing for various metals and non-metallic stock are performed in the first cut area. The major equipment are : Metora NC Horizontal Band Saw : Band Saw Angle : 16’9’’ * 1’’ 1/2 * 0.050’’ Max.Cutting Length : Single Index : 20’’ Multiple Index : 180’’ Long blocks of metals are cut with this machine . Tsman Plate Saw : Capacity ( Non-ferrous ) : 6.25’’ * 48’’ * 144’’ Material Handling Table : 60’’W * 156’’L Spindle Travel ( Longitudinal ) : 156’’ Feed Rate : 0-20 fpm Large blocks of metals are cut with the plate saw . Cincinnati Skin Mill : Table Capacity : 124’’ * 60’’ Face Mill Diameter : 18’’ Face Mill Inserts : 12 pcs Speed Range : 1750-3500 rpm Skin Mill is used to mill the surfaces of metal blocks .
7
Wellsaw Power Hack Saw : Saw Type : 57Horiz./Vert. - W20 Vert Capacity : 5’’H*7’’W - 16’’H*20’’W, 5’’Dia Approx. Shipping Weight : 74 - 318 kg 2 Tannewitz Vertical Band Saw : Machining Capacity : 35’’1/2 Work Thickness : 20’’ Wheel Diameter : 36’’ Blade Width : 0.3175 - 5.08 Size : 36’’ * 36’’ Koihe - Sanso Plasma / Flame Cutting Machine : Capacity : Steel up to 8’’ , Aluminum up to 6’’ Tracing Dimensions : 100’’ * 120’’ Cutting Dimensions : 120’’ * 65’’ Number of Torches : 3 oxy + 1 plasma Tracing Speed : 4-62 in/min 2 Cincinnati Mechanical Shears : Blade Length : 12ft Capacity : 1/4’’ Mild Steel 1/10’’ stainless steel 1/4’’ aluminum 1/10’’ titanium These machines are used to first cut sheet metals.
3.1.2 Turning : External cylindrical and conical surfaces are machined on manual, NC, and also on turret lathes in the turning area. Major equipment in turning area are: Mazak Quickturn CNC Lathe : Computer numerical controlled pneumatic clamp, hydraulic movement, electric motor. Turning Diameter : 7.1’’ Turret : 12 Swing over bed : 15.7’’ Spindle speed range : 45-4500 rpm Large quantities of precise pieces are produced.
8
Mazak Universal Engine Lathe : Swing over bed : 21’’ Swing over crossslide : 13’’ 1/8 Max distances btw. centers : 80’’ Spindle speed range : 25-2000 rpm Large and long workpieces are turned on this machine. 5 Herbert Turret Lathes : Max. turning length : 14 1/2’’ Max. diameter of workpiece : 3’’ Swing over overhead : 15 3/4’’ Swing over crosslide : 8 3/8’’ Turret : 6 Takisawa CNC Turret Lathe : Max. length of workpiece : 4’’ Turning diameter : 7.1 Swing over bed : 15.7’’ Spindle speed range : 45-4500 rpm Turret : 12
3.1.3 Milling : All types of milling operations with Universal or Vertical Milling Machines, NC Vertical Machining Centers for complicated/multistaged manufacturing, Tracer Milling/Copy Machines with single or multi-spindles, Skin Milling for wide-surface works, Electrical Discharging/Spark Eroding Operations both for tooling and fabrication purposes are performed in the milling area. Because the milling process is versatile and highly productive, a variety of machines have been developed to employ the milling principle. The equipment used in this area are : Cincinnati 3 Axes Vertical Milling Machine : Column and knee type. Table size : 94’’1/2 Max. distance btw table/spindle : 21’’9/16 Column to spindle axis distance : 20’’1/2 2 Cincinnati 4 Axes Horizontal Milling Machines : Column and knee type. Vertical milling attachments can be used .
9
Max. workpiece size : 32’’ length, 15’’ width, 10’’ height 8 Cincinnati 5 Axes Horizontal Milling Machine : The machine is column and knee type, and has the universal milling attachment. It is used in milling tooling parts. Table size: 80’’ * 18’’ Max. distance between the table and the spindle : 19’’3/4 Throat : 40’’13/16 Max. workpiece size : 32’’ length, 15’’ width, 10’’ height Rambaud Copy Milling Machine : Table size : 103’’ * 25’’ Table longitudinal travel : 40’’ Ram cross travel : 20’’1/4 Column to spindle axis travel : 7’’7/8 Number of spindle : 2 Gorton Copy Milling Machine : Table size : 45’’1/2 * 9’’ Table longitudinal travel : 24’’ Ram cross travel : 12’’ Column to spindle axis distance : 10’’1/2 Elox Electrical Discharge Machine : Table size : 40’’ * 24’’ Distance btw. spindle axis/table : 19’’3/4 Throat : 40’’13/16 Electrodischarge machining(EDM), cuts metal by discharging electric current stored in a capacitor bank across a thin gap between the tool(cathode) and the workpiece(anode). Literally thousands of sparks per second are generated and each spark produces a tiny crater by melting and vaporization, thus eroding the shape of the tool into workpiece. The dielectric fluid (kerosene) flushes out the chips and confines the spark. Materials of any hardness can be cut as long as the material conducts electricity. The absence of almost all mechanical forces makes it possible to machine fragile parts without distortion .On most materials, the process produces a thin, hard recast surface, which may be an advantage or a disadvantage, depending on the use.
3.1.4 Grinding :
10
Large capacity-wide surface grinding with Vertical Surface Grinders, surface grinding with reciprocating magnetic work table and moving grinding wheel, Rotary Surface Grinding with the workpiece mounted magnetically to the rotary table, Centerless Grinding, Internal/External Grinding of cylindrical surfaces, general purpose grinding either for single or lot production, Taper/Concave/Convex Grinding with Universal Grinders are performed in this area . Blanchard Vertical Surface Grinder : Magnetic chuck diameter : 66’’ Swing capacity : 84’’ Max. unbalanced load on chuck : 10000 lb. Grinding wheel size : 36’’ Thomson Surface Grinder : Work capacity : L=40’’ , W=16’’ , H=22’’ Grinding wheel diameter : 20’’ Cincinnati Centerless Grinder : Work diameter range : 1/16’’ - 4’’3/4 Grinding wheel diameter : 15’’ - 20’’ Distance btw. wheel axis : 12’’1/2 - 22’’3/4 Regulating wheel diameter : 9’’1/2 - 12’’ Centerless grinding makes it possible to grind both external and internal cylindrical surfaces without requiring the workpiece to be mounted between centers or in a chuck. This eliminates the requirement of center holes in some workpieces and the necessity for mounting the workpiece, thereby reducing the cycle time. Cincinnati Heald Internal Grinder : Max. swing over table : 19’’1/2 Max. swing inside Table : 24’’1/2 Distance between wheel & chuck : 30’’ Cincinnati Universal Grinder : Max. swing over table : 14’’15/16 Max. diameter of grinding : 14’’15/16 Max. distance between centers : 48’’ Regular grinding wheel diameter : 14’’
3.1.5 Tool & Cutter Grinding :
11
Complete range of cutter and tool grinding operations such as radius, drill point, universal tool, flute, tap, saw, counter grinding and honing is performed. This group is designed to meet all demands of assembly, tooling, and fabrication activities. The major equipment used in this area are : Cincinnati Tool & Cutter Grinders 2 Pratt & Whitney Radius Grinders 4 Winslow Drill Point Grinders Cincinnati Universal Tool Grinders Hybo Flute Grinder Original Vollmer Saw Grinder Walter Counter Grinder Sunner Hone Honing Machine Simple, single-point tools often are sharpened by hand on bench or pedestal grinders(offhand grinding). More complex tools, such as milling cutters, reamers, hobs, and single-point tools for production-type operations, require more sophisticated grinding machines, commonly called universal tool and cutter grinders.
3.1.6 Drilling & Boring : All types of drilling operations with various types of Drilling Machines : drilling, milling, facing & scribing with Jig Borers and NC Jig Milling are performed. The major equipment are : Waida, Pratt & Whitney Jig Borers : Table size : 25’’1/2 * 43’’ Table movement (Transverse ) : 2’’ Table movement (Longitudinal) : 39’’3/8 Boring head vertical movement : 17’’3/4 Drilling capacity : 2’’ (cast iron) , 1’’1/2 (steel) , 10’’ max. drill. cap. Moore Jig Borer : Table working surface : 19.5’’ * 11’’ Table longitudinal travel : 14’’ Table cross travel : 10’’ Spindle head vertical travel : 10’’
12
Pratt & Whitney Jig Borer : Table working surface : 24’’*55’’ Table longitudinal travel : 48’’ Table cross travel : 24’’ Standard feed range per revolution : 0.0005’’ - 0.0010’’ 2 Pratt & Whitney CNC Drill ( TAPE-O-MATIC ) : Drilling capacity in mild steel : 2’’ Table working surface : 45’’*29’’ Table travel : 40’’ (longitudinal) , 26’’ (transverse) Head vertical adjustment : 22’’ Floor to top of table : 32’’ These machines are used for progressive drilling, reaming, and related operations. Kitchen & Walker Radial Drill : Spindle travel : 15’’ Spindle tape morse : 5 Head travel : 70’’ Arm travel : 30’’ Feed range per rpm : 0.0023’’ - 0.029’’ No of spindle speed : 18 Cleereman Box Column Drill : Table working surface : 13’’46’’ Table longitudinal travel : 48’’ Table cross travel : 18’’ Table top to spindle nose : 22’’ No of spindle speed : 12
3.2 CNC Machining : Drilling, Boring, Milling, Taping of aluminum and steel, either for single parts or lot production, both for tooling and fabrication purposes are performed in the CNC Machining Area. The major equipment used are : Hitachi CNC Machining Center, 3-Axis : Table size : 66’’ * 22’’ Travel : X-55’’ , Y-23’’5/6 , Z-21’’5/6 No of turrets : 30 Distance from spindle to table top : 44’’ 3 Giddings & Lewis CNC Machining Center, Vertical, 3-Axis :
13
Working Surface : 80’’ * 40’’ Travel : X-80’’ , Y-40’’ , Z-40’’ No of turrets : 40 Distance from spindle to table top : 44’’
3.3 NC Machining : There are various types of vertical and horizontal Numerically Controlled Machine Tools which are capable of milling, drilling, reaming, boring, facing, tapering, tapping, and pocketing all kinds of metal parts with a wide variety of sizes, used in the aerospace industry. The programming of these NC machines are performed in the NC PROGRAMMING department with the use of a computer language called APT(Automatically Programmed Tools). Postprocessing takes the output from the APT program and converts it to input for a particular machine. Through the use of either tape or computer control, there can be good assurance that consecutive parts are duplicated and that a part made at some later date will be the same as the made today. Thus, repeatability and quality are improved. NC Machine Tools are grouped as follows : Machining Centers ; which are sophisticated, multi-axis NC Machine Tools with more than one work holding fixtures. They are capable of drilling, reaming, milling, tapping on multiple faces of a part and can hold from 40 to 60 cutting tools at a time in an automatic tool changer system. Profiler Mills ; which are capable to perform a wide variety of milling, profiling, tapering, and pocketing operations on multiple faces of large complex aircraft components. These machines can duplicate external or internal geometry’s in two dimensions. Boring Mills ; which are capable to perform drilling, tapping, milling, and boring operations on multiple faces of a part and are equipped with automatic tool changer system. Tracer Mills ; which are capable to machine one to six parts of the same configuration at the same time by utilizing tracing head which traces a 3-dimensional pattern. They roughly machine production parts which later will be finished on various types of CNC equipment.
14
Giddings & Lewis Machining Center, 5-Axis : Axis travel : X-48’’ , Y-42’’ , Z-30’’ , A-110 , B-360 Work surface : 32’’ No of tools : 48 Sundstrand Omnimills Machining Center, 5-Axis : Axis travel : X-48’’ , Y-60’’ , Z-54’’ , A-150 , B-360 Work surface : 42’’ No of tools : 60 Sundstrand Machining Center, 4-Axis : Axis travel : X-40’’ , Y-32’’ , Z-26’’ , B-360 Work surface : 26’’ No. of tools : 40 Cincinnati Milacron Gantry Profiler, 5-Axis, 3 Spindle : Axis travel : X-600’’ , Y-164’’ , Z-28’’ Work surface : 160’’ * 720’’ No. of spindles : 3 Wilson CNC Profiler, 4-Axis, 2 Spindle : Axis travel : X-144’’ , Y-60’’ , Z-24’’ Work surface : 240’’ * 84’’ No. of spindles : 2 Giddings & Lewis Machining Center, 4-Axis, Horizontal : Axis travel : X-360’’ , Y-103’’ , Z-48’’ Work surface : 360’’ * 120’’ Rotary table diameter : 72’’ No. of tools : 40 Giddings & Lewis Boring Mill, 3-Axis, Horizontal : Axis travel : X-144’’ , Y-67’’ , Z-36’’ , W-50’’ Work surface : 144’’ * 60’’ Wilson Tracer Mills, 6-Spindle, Vertical : Axis travel : X-144’’ , Y-48’’ , Z-24’’ Table size : 78’’ * 169’’ No. of tools : 6
15
3.4 Sheet Metal Fabrication : Sheet Metal Fabrication Shop has various types of metal cutting and forming machines which can produce a wide variety of F-16 aircraft parts. Sheet Metal Fabrication Processes are : Fluid Cell Forming Roll Forming Braking, Bending, & Joggle Forming Stretch Forming Drop Hammer Forming Punching, Piercing & Blanking Routing Hand Routing Deburring
3.4.1 Fluid Cell Forming : Forming sheet metal a/c parts such as recessed parts, all kinds of flanges including C-shaped ones and generally for more complex parts with re-entrant features. The socalled Hydroform process utilizes the phenomenon that rubber of the proper consistency, when totally confined, act as a fluid and will transmit pressure in all directions. The form blocks can be made of wood, bakelite, polyurethane, epoxy, or low-melting-point zinc alloys (such as kirksite ). As the ram of the machine descends, the flexible diaphragm is confined and transmits force to the metal, causing it to bend to the desired shape. Since no female die is used and inexpensive form blocks replace the male die, tooling cost is quite low. Process flexibility is quite high that different shapes can be formed at the same time. Wear on the material and the and tooling is low, and the surface quality of the workpiece is easily maintained. ASEA Brown Bowery Quintus Fluid Cell Press : Max. forming pressure : 140Mpa Max. press force : 72000 tons No. of tray loading stations : 2 Max. tray width : 10’’10/16 Tray area : 47’’4/16 * 118’’1/8 Average cycle time : 150 sec. This is the only machine used in Turkish Industry which has a capacity of 140Mpa of a forming pressure and 72000 tons of a press force. A very special diaphragm is used.
16
Elongation of the diaphragm is minimized by correct spacing and by locating the form blocks, and proper utilization of equalizing rubber strips and sheets.
3.4.2 Roll Forming : Edge forming, rolling as well as pressing of aluminum alloys with a maximum plate thickness of 5mm at full width. The equipment used are : Haeusler Sheet Roll : Capacity : 3/16’’ * 12’’ in 2024T6 aluminum Roll diameter : 3’’ Max. upper roller pressure : 100 tons Max. working width : 12’’(3660 mm)
3.4.3 Braking, Bending & Joggle Forming : Single and multiple straight line bends in sheet metal parts are formed. Hot and cold joggles of all lengths and depths in all flats and extrusion materials are performed. The major equipment used are : Cincinnati Mechanical Press Brakes : Capacity : 150 tons Max. die length : 12’’ Bending capacity : 1/4’’ * 12’’ The machine is used for forming rounds and angles on sheet metals. Wysong Press Brakes : Bending capacity : 35 tons Punching capacity : 20 tons National Machine Tool Builders Joggle Press : Type : Four Post Hydraulic Capacity : 75 tons Stroke : 20’’ Work height : 26’’ Work area : 30’’ * 37’’ This machine is used to form joggles using simple and compound die sets. Especially simple joggles are formed here, and the more complex ones are formed in the hydraulic press.
17
3.4.4 Stretch Forming : Almost any shape which is very difficult or impossible to produce by other forming methods can be produced by stretch forming. The process is developed by the aircraft industry to enable sheet metal parts, particularly large ones, to be formed economically in small quantities. Only a single male form block is required. The sheet of metal is gripped by two or more sets of jaws that stretch it and wrap it around the form block as the latter rises upward. There is very little springback, and the workpiece conforms very closely to the shape of the form block. If mating male and female dies are used to shape the metal while it is being stretched, the process is known as stretch-draw forming. The basic equipment used are : Cyrill Bath Stretch Press Brake : Capacity : 150 tons(brake) , 50 tons(stretcher) Bed length (brake) : 168’’ Ram stroke : 8 Max. distance between jaws : 168’’ Cyrill Bath Draw Press : Press ram tonnage : 400 tons Shut height (strokedown) : 52’’ Longitudinal stretch force : 250 tons Max. workpiece size : 72’’ * 144’’ Effective jaw length : 72’’ Max. distance between jaws : 160’’ Cyrill Bath Stretch Form Press : Die table tonnage : 750 tons Die table stroke : 82’’ Die table length : 100’’ Jaws stroke : 72’’ Max. distance between jaws : 144’’ Cyrill Bath Stretch Wrap Former : Tension cylinders tonnage : 30 tons Tension cylinders stroker : 30’’(out) Arm cylinder stroke : 46’’ Max. distance between jaws : 200’’ The parts having complex shape and sheet plates with high thickness are formed with this machine.
18
3.4.5 Drop Hammer Forming : Production of the desired shapes by progressive deformation of sheet metal in matched dies are performed. Configurations include shallow, smoothly contoured double curvature parts, shallow-beaded parts and parts with irregular and comparatively deep recesses. Irregular and deep shapes that can not be formed by hydroform press because of the excessive depth are formed using suitable male and female dies. The workpiece is placed between the dies and impact force is applied a few times. Chambers Burg Drop Hammers : Min. die area : W=29.0’’ * L=25.5’’ Max. die area : W=90.0’’ * L=40.0’’ Chambersburg Double Frame Pneumatic Drop Hammers : Min. die area : 46’’1/2 * 42’’ Max die area : 48’’ * 60’’ Chambersburg Double Frame Pneumatic Drop Hammer : Min. die area : 68’’ * 34’’ Max. die area : 49’’ * 69’’
3.4.6 Punching, Piercing & Blanking : Punching, piercing, blanking, notching and cutting of ferrous/non-ferrous material are performed. Piercing & blanking are shearing operations wherein the shear blades take the form of closed, curved lines on the edges of a punch and die. They involve the same basic cutting action with a difference being ; in blanking, the piece being punched out is the desired workpiece and any major burrs or undesirablefeatures should be left on the remaining strip ; in piercing, the piece being punched out is the scrap and the remainder of the strip becomes the desired workpiece. The equipment used are : Minster Punch Press : Capacity : 75 tons Shut height : 18’’ * 21’’ Stroke/Slide : 4’’ Stroke per min. : 90 Size : 17’’ * 30’’ Wiedemann Turret Punch Press : Capacity : 15 tons
19
Ram stroke : 11/16’’ Stroke per min. : 175 Max.. sheet size : 28’’ * 40’’ Turret punch press is capable to put 20 different types of punches in turret in one set-up to punch multiple shapes into production parts. 2 Scothman Iron Worker : Piercing/Punching of the holes up to 1’’.
3.4.7 Routing : Cutting/Trimming of the sheet metal parts to their net size is performed in routing area. The major equipment used are : Marvin Two Spindle Tracer Router : Table size : 144’’ * 47’’1/2 Spindle stroke : 4’’ Max. work size : 35’’ * 144’’ Speed : 10800 rpm Orton Tilting Spindle Shaper : Table size : 40’’ * 60’’ Speed : 10000 rpm Tilting angle : 45 Onsrur Broken Arm Router : Table size : 49’’ * 158’’ Speed : 14400 rpm Max. vertical head travel : 6’’ Max. capacity : 5/8’’ thick aluminum Watkin Heavy Duty Articulated Arm Router : Min. effective radius of arm : 2’ 1 1/2’’ Max. effective radius of arm : 6’ 2 1/4’’ Rise and fall of head in slider : 12’’ Stroke movement of head : 4’’ CNC Router : Max. load of table : 500 kg/square meter Max. speed of axes : X-Y 40 m/min , Z 5 m/min Max. thickness of the workpiece : 3.9’’ Max. workpiece size : 590’’ * 1528’’
20
12 tools, 3-axis. Only aluminum sheets are routed. The machine has a pneumatic head with 6bar air pressure. Complex shapes can be cut. With the help of a system called nesting, material waste is minimized. 3 Ro-117 Table Routers : Table area : 31’’7/8 * 19’’3/4 Spindle speed : 20000 rpm Boring, face shaping, edge routing, carving, embossing, grooving and other types of routing operations are performed with these machines.
3.4.8 Hand Routing : Trimming and edge cutting of complex shaped parts are produced in the Hand Routing area. There are 6 Pneumatic Hand Routers which are used for final cutting of complex, non-flat sheet metal parts that can not be routed with the other routers because of the curvatures. Suitable templates are used as production aids.
3.4.9 Deburring : Burrs form on the edge of all machined and stamped parts and in most of the cases they should be removed. Burrs are generally small, sometimes flexible projections adhering strongly to the edge of the workpiece. They are typically .003 in. thick and .001 to .005 in. high. If they are not removed they can cause assembly failures, short circuits, injuries to workers, and even fatigue failures. Most deburring processes remove metal from exposed surfaces while removing burrs. Because burr size is not controllable it is important to allow some tolerances on part dimensions and edge radii for deburring. The process is done either by hand or applying vibration principle with : Almco Vibratory Deburring Machine : The machine contains some special stones and by tumbling removes the burrs. There is also a task center called Hand Finishing in Sheet Metal Forming Area. Some sheet metal workpieces go finally to hand finishing to be given the exact shape. Especially the sheet metals after being stretch formed spring back and these pieces are corrected by hand finishing.
3.5 Tubing & Welding :
21
Tubing details, assemblies of steel and aluminum usable under high or low pressure are manufactured, and also all welding required for the manufacture and repair of detailed parts and assemblies are performed. Tubing Operations : Perma Swage Dyna Swage Wiggins Swage Vaill Swage Single & Double Flare Beading Bending Welding Operations : Numbering & Identification Tack Welding Steel Welding (including titanium) Aluminum Welding Chemical Clean Pressure Test
3.5.1 Welding : Welding is a process in which two materials, usually metals, are permanently joined togetherby coalescence, the coalescence resulting from a combination of temperature, pressure, and metallurgical conditions. Welding can be accomplished under a wide variety of conditions, and numerous welding processes have been developed and are used routinely in manufacturing. Suiting homogeneous joining of most grades of carbons, stainless steels, aluminum, magnesium ; alloys of above metals and hard-surfacing and high-temperature alloys, metals such as titanium, zirconium, gold and silver are performed. Through these processes, optimum thickness of sheet material is 1/4’’. 6 Miller TIG Welding Machines : Dimensions : L=23’’ , W=31.5’’ , H=44’’ PRIMARY Volts : 220/380/440 Ampere : 165/96/83s Single-Phase : 50 Hz
SECONDARY Volts : 32 Ampere : 300 Duty cycle:60%
Stainless steel, aluminum, magnesium, titanium, zirconium, gold & silver can be welded with these machines using argon gas and tungsten electrodes. A tungsten electrode is positioned in a special holder through which inert gas flows to form an inert shield
22
around the arc and pool of molten metal. Alternating current is used for aluminum welding and direct current is used for steel welding. 4 Tokar Weld Cleaner : Dimensions : L=36’’ , W=36’’ , H=16’’ Bucket : 11’’ * 11’’ Basket : L=26’’ , W=26’’ , H=16’’ Crane capacity : 500 kg The tanks are used to clean the aluminum for the preparation of welding by removing chip at the rate of .00005 + .0001’’/surface/minute. These are : 1- Alkaline clean : ( 71-78 C ) 5-15 min 2- City water rinse : ( 60 C ) 2-5 min 3- Acid clean : 4- City water rinse : ( 60 C ) 2 min 6 Aircrafter Welding Positioner : Dimensions : L=11’’ , W=8’’ , H=7’’ Capacity : 100 lb. Table diameter : 7’’ Table rotation : Forward-off-reverse This machine is suitable for jobs which require rotary fixturing and positioning and capable to handle properly balanced loads up to 100 lb., at the horizontal position.
3.5.2 Baking : Istas Baking Oven : Dimensions : L=119’’ , W=59’’ , H=59’’ Max. temperature : 300 C Capacity : 50 kW The oven is used for any air or fluid system item made from corrosion and heat resistant alloys, nickel alloys and all other metals (except aluminum), sufficiently complex that complete drying of interior surfaces can not be visually verified to prevent corrosion after pressure testing with water.
23
3.5.3 Swaging : Swaging involves hammering or forcing a tube or rod into a confining die reducing its diameter, tapering, or pointing round bars or tubes. The die itself often plays the role of the hammer. Wiggins Swage Machine Tube size (outer diameter) : 3’’ Dyna Swage Machine Tube size (outer dia.) : 1/4’’ * 5/4’’ Perma Swage Machine Tube size (outer dia.) : 3/2’’ Vail Swage Machine Tube size (outer dia.) : 3’’
3.5.4 Pressure Testing : ACL Thecnologies Low Pressure Test Stand : Test medium : water System pressure : up to 1800 psig (static) Pressure pump : Air-driven (0-1850) psi Capable to perform low pressure water test of hose and tube welding assemblies. The test pressure is twice as much of the operating pressure the tube is exerted in the plane. ACL Technologies High Pressure Test Stand : Test Medium : hydraulic oil System pressure : up to 10000 psig (static) Test Pressure : 6000 psi max. Max. tube assembly diameter : 1/8’’ to 1 1/2’’ Capable to perform high pressure test of swaged tubes. Again the test pressure is twice as much of the operating pressure.
24
3.5.5 Flaring, Squaring and Bending : Concrac 2-3 CP Flaring, Squaring, Beading Machines : Max. tube diameter : 3/8’’ - 3’’ Preparing the tubes for process, single and double flare, squaring and beading operations are performed.
3.5.6 Tube Bending : Fully automatic NC Tube Benders capacities of which depend on the type of materials, wall thickness and centerline radius are used. 5-axis machines are enable to measure tube shapes with minimum interference. NC Tube Benders, Hand Benders and Coil Benders have bending range from 1/8’’ to 3’’ (OD) and up to 16 bends on every tube. The equipment used are: Eaton Leonard NC Tube Benders : Max. tube sizes (outer dia. ) : 1/2’’ - 1’’1/2 Max. bend angle : 195 There semi-automatic and automatic tube benders in tube bending area. On semiautomatic NC tube benders only bending is done by hand force, other operations (adjusting the length, the twist angle and the bending angle) are done automatically. Automatic NC tube benders make all the necessary operations by itself after taking the tube. Hand Benders : Max. tube size ( outer dia. ) : 1/8’’ - 3’’ 2 Coil Benders : Bending capacity (outer dia. ) : 3/8’’ - 1/4’’ Max. length of tube : 59’’ The machine is manual and all coil bending operations are performed with these machines.
3.5.7 Degreasing : Vapor degreasing is widely used to remove oil from ferrous parts and from such metals as aluminum and zinc alloys, which would be attacked by alkaline cleaners. A nonflammable solvent, such as trichloroethylene, is heated to its boiling point, and the
25
parts to be cleaned are hung in its vapors. The vapor condenses on the work and washes off the grease and oil. Excess vapor is condensed by cooling coils in the top of the cooling chamber. Vapor degreasing is effective only if the vapor condenses on the work. Thus the work must remain relatively cool. Vapor degreasing is a rapid process and has almost no visible effect on the surface. If the surface has substantial solid dirt in addition to oil, this is removed by passing the work through a boiling liquid, thereby removing most of the dirt and some of the oil, then through cold liquid to cool the work, and finally through hot vapor to remove the remaining oil. Some solvents used in degreasing are: Trichloroethylene : For removing semicurred varnish or paint films, heavy rosins and buffing compounds. Perchloroethylene : It has a high boiling point, so it is excellent for removing high melt waxes and for cleaning light-gauge metal parts. 1,1,1-trichloroethane : For printed circuit boards, electronic components and electrical motors. Methylene chloride : It has a low melting point, so it is preferred for temperature sensitive parts and where aggressive solvency is needed. Vapor degreasing is a rapid process and has almost no visible effect on the surface. The degreaser used in TAI is capable to clean a/c sheet metal parts and tubes. Parts receive a vapor wash, spray distillation, vapor drying and leave degreaser clean and dry. 2 Baron-Blakeslee Vapor Degreaser : Type : vapor wash and distillate spray Vapor column : 60’’ Storage tank : 250 gallons Max. load : 6000 lb./hr Tank size : L=192’’ , W=30’’ , D=60’’ One load of Al : 1500 lb.
3.6 Tooling :
26
Tooling plays an important role on manufacturing. Tools are used to hold, cut, shape, or form the unfinished product. Tools also include work holders, jigs, and fixtures. Every part to be manufactured have to have a planning, so the first thing before production is planning. Planning department make a production plan an states the operation sequence. In general a tool order is released for the parts that can not be manufactured easily with general purpose work holders. The technical drawing of the part called the blue print and all the necessary knowledge about the part goes to the tool design department. After the tool have been designed, tool manufacturing starts. A very important consideration of tools is that ; it is possible to produce the same part with the same accuracy after many many years. Tooling for F-16 aircraft is finished so there is nothing difficult in manufacturing the aircraft. The only thing to do is to follow the same sequence. Molding, casting, surface finishing of Stretcher Draws (STDW), Drop Hammer Dies (DHDI) and Stretcher Forms (STFM) using kirksite or lead as material are performed. The major equipment used are : Unberg Pot Furnace, Hand Tilting : Type : 61-RNL-80-P Max. casting capacity : 6500 lb. for kirksite Max. temperature : 900 F Used for melting the casting material and pouring it into the die. EMC Spotting Press : Max. working dimensions Length : 96’’ Width : 48’’ Height : Adjustable Type : Hydraulic, 4-Column The press is used for pressing the sand mold to be used for sand casting. Beardsley & Piper Sand Slinger : Model : 10 tons, Roto Feed The machine is used for flinging sand into the flask with high velocity for better uniformity and compacting.
27
Cincinnati Universal Milling Machine : Table Total surface : 63’’ * 14.4’’ Width of T-slots : 5 Longitudinal feed : 39.6’’ Cross feed : 13.2’’ Vertical feed : 19.0’’ Rapid traverse Longitudinal : 9.2’’/min Cross : 9.2’’/min. Vertical : 6.6’’/min. Milling arbor diameter : 1’’ - 1’’1/4 Usable length : 22.6’’ The machine is used for producing tools from metal blocks. Rockford NC Planer : Stroke length : 60 * 60 , 72 * 72 Stop pin holes diameter : 10’20’ Tee bolt diameter : 1’’ Depth of table over tee : 13-7/8 Column face-width : 18’’ Feeds (vertical & horizontal) : infinite (0.005’’ - 1.0’’ Used in production of large tooling parts. 3 Ro-117 Table Routers : Table area : 31’’7/8 * 19’’3/4 Spindle speed : 20000 rpm These 3 routers are used for producing flat templates to be used in routers, using a production sample. Film Processor : The machine is used for copying lofts. Shot Machine : Uses strong and colored lights to copy the lofts over the sheet metals. Film Developer : The special chemicals in the developer makes the loft prints on the sheet metals visible.
28
Naber Electrical Oven : Operating temperature : 1600 C The oven is used in tempering tools. 2 Blue Em Electrical Ovens : Operating temperature : 1400 C The oven is used in tempering small tools. Aube-Lindberg Oven : Operating temperature : 1200 C Used in tempering small tooling parts. G & L Bickford Chipmaster Radial Drill : The machine is used in drilling tooling parts. Taksan Surface Grinder : The machine is used in all grinding operations of tooling parts. 2 Cleereman Box Column Drill : Table working surface : 13’’ * 46’’ Table longitudinal travel : 48’’ Table cross travel : 18’’ Distance from table top to spindle nose : 22’’ No. of spindle speed : 12 These machines are used in drilling and reaming operations where that operations can not be performed with milling machines because of the positions of the holes.
3.7 Chemical Processing : TAI Chemical Process Facility is one of the most advanced and one of the largest of its kind in the Middle East and Europe, operating with the most developed technology and with the highest capacity. The facility covers an area of 29,600 square feet (2500 sq. meters) under roof, and is equipped with : Automatic sprinkler type of fire system Ventilation system preserving the building atmosphere under positive air pressure DI and RO water treatment systems providing deionized water to process tanks
29
Automatic pumping system discharging chemical wastes into industrial waste treatment Six overhead cranes (4 are 1 ton and 2 are 1/2 tons capacity) Chemical Milling is utilized to replace Machine Milling operation and to produce patterns on aluminum parts at different thickness and reduce weight. There are seven task centers to accomplish the chemical processes : Aluminum Chemical Processing
Chemical Milling Chromic Acid Anodizing Chemical Film Coating Prepenetrant Etch Cleaning of Aluminum Electrical Bonding Stainless Steel Processing
Passivation Prepenetrant Etch Cleaning and Descaling Stainless Steel
3.7.1 Cleaning, Coating & Anodizing of Aluminum : There are 16 aluminum dipping tanks. The dimensions of the Al dipping tanks are : L=6.1m , W=1.2m , H=3.1m. Preperation of the parts for chemical milling is performed in these tanks. Degreasing, cleaning, rinsing and precleaning operations are performed to provide good adhesion for masking material. The tanks are placed in order : 1. Vapor degrease tank : Trichloroethylene vapor at 91C is used to degrease the parts. The process takes 3-5 minutes. 2. Alkaline clean tank : Turco emulxlene 3878 at 52-57 C is used to clean the workpiece by very little material removal. Max.operation time is 15 minutes. 3. Flash etch tank : Sodium hydroxide, sodium sulfahydrate and sorbitol mixture is used for pre-penetrant etch cleaning. The process takes 1.5 minutes.(Max.)
30
4. City water rinse tank : The tank contains city water at ambient temperature. Used to clean the remains of the tanks the part is dipped before. 5. Acid cleaner tank : Chromic acid, nitric acid and hydrofluoric acid mixture at ambient temperature is used for cleaning the surface by removing material. The material removal rate is 1/100000’’. The dirt, corrosion and other foreign materials are cleaned. 6. Deoxidizer tank : A mixture of chromic acid, nitric acid, and hydrofluoric acid at ambient temperature is contained in the tank. Main material removal process takes place before anodizing and coating. 7. City water rinse tank : City water at ambient temperature rinse the workpiece. 8. City water rinse tank : Does the same work. 9. Deionized water rinse tank : This is the last tank before chemical processes. Deionized water at 66C is used to clean the workpieces, especially thin tubes. 10. Chromic acid anodize tank : Anodizing is a process widely used to provide corrosion resistant and decorative finishes to aluminum. Chromic acid anodizing at 33-38 C is done in this tank. The workpiece is coated with dialuminumtrioxide, which prevents oxidation and conductivity, by electrolyzing. It is somewhat the reverse of electroplating in that (1) the work is made the anode in an electrolytic circuit and (2) instead of a layer of material being added to the surface, the reaction progresses inward, increasing the thickness of the highly protective but thin aluminum oxide layer that normally exists on aluminum. It is used primarily on aircraft materials. Because the coating is integral to the part, the metal can be subjected to quite severe forming and drawing operations without destroying the coating or reducing its protective qualities, anodizing is performed after all these operations are done in TAI. Parts that are anodized in this manner have a grayish-green color resulting from the presence of chromium in the coating. Inasmuch as anodizing does not add to the dimensions, there is no necessity for providing any dimensional allowance. 11. Deionized water rinse tank : Deionized water at ambient temperature cleans the chromic acid over the surface of the workpiece.
31
12. Seal tank : Sodium dichromate at 88C seals the tiny holes and defects on the part after chromic acid anodize operation. 13. Deionized water rinse tank : The water is at ambient temperature. Workpieces are rinsed in the tank. 14. Chemical Film (Chem film) tank : The workpiece is coated with dialuminumtrioxide and dichromtrioxide which prevents corrosion and permits conductivity. 15. Deionized water rinse tank: The water is at ambient temperature. 16. Deionized water rinse tank : The water is at 60C. The tank is used for final cleaning of the workpiece.
3.7.2 Chemical Milling Process for Aluminum : There are 7 aluminum dipping tanks dimensions of which are : L=6.1 m , W=1.2 m , H=3.1 m. 1. Wax tank : The thinned wax coats the workpiece in 15 sec. and dries. The process is repeated twice for the wax to coat the workpiece uniformly. After masking the whole surface of the workpiece with the wax, we cut off the sections to be milled. If all areas are to be machined to the same depth, only a single immersion is enough, but if the machining is to be done to two or more depths, called step machining, we have to remove the mask in a sequence. Chemical machining has a number of distinct advantages. The process is relatively simple, does not require highly skilled labor, induces no stresses or cold working in the metal, and can be applied to almost any metal-aluminum, magnesium, titanium, and steel being most common. The tolerances expected with chemical machining range from 0.0005 in. with care on small etch depth to 0.004 in. in routine production involving substantial depths. The surface finish is good, seldom having a roughness greater than 0.0001 in. 2,3. Chemical milling tanks : There 2 chemical milling tanks each of them containing sodium hydroxide, sodium sulfahydrate, sodium aluminate, and sorbitol at 85-90 C. Chemical etching at a certain rate occurs. After the desired depth is reached, the workpiece is taken out of the tank.
32
4. City water rinse tank : The water at ambient temperature is used to clean the workpiece from chemicals. 5. Desmut tank : There is a mixture of chromic acid and hydrofluoric acid at ambient temperature. The black toxic layer caused by chemical etching is removed from the surface of the workpiece. 6,7. City water rinse tank : There are 2 city water rinse tanks which cleans the chemicals with water at ambient temperature.
3.7.3 Passivation, Pre-penetrant Etch Cleaning and Descaling of Stainless Steel : There are 12 steel dipping tanks with dimensions L=1.8m , W=1.2m , H=1.8m. These are : 1. Vapor degrease tank : Trichloroethylene vapor at 91C is used to clean the workpiece before chemical processes. 2. City water rinse tank : Water is between 27C - 60C. 3. Alkaline cleaner tank : A mixture of potassium permanganate, sodium hydroxide and sodium carbonate at 88C-104C is used to clean the workpiece roughly. 4. Descale tank : A mixture of nitric acid, phosphoric acid, hydrochloric acid and biversey ds-9-304c is used to remove material from the workpiece. 5. City water rinse tank : Water at ambient temperature to remove chemicals. 6. Deionized water rinse tank : Deionized water is at 60C-71C. 7. City water rinse tank : The same tank with the 5th tank. 8. Neutralizer tank : Sodium dichromate at 60C-71C is used to neutalize the workpiece by rearranging the ions at the surface. 9. Inhibited acid brightenge tank : Alkyl inhibitor and hydrochloric acid mixture cleans the surface of the workpiece by removing very small amount of material. 10,11. City water rinse tank : 2 tanks containing city water at ambient temperature.
33
12. Steel passivation tank : Sodium dichromate and nitric acid at 49C-54C passivate the workpiece. The finishing systems provide the process of applying corrosion resistant coatings to aircraft aluminum and stainless steel parts. An area for titanium processing has also been assigned for future requirements. There is also a liquid penetrant inspection unit in chemical processing building. Liquid penetrant testing, which is a simple method of detecting surface defects in metals and other nonporous material surfaces, is performed. The piece to be tested is first subjected to a thorough cleaning, often by means of solvent-type materials, and is dried before the test. Then , a penetrant is applied to the surface of the workpiece by dipping, spraying, or brushing. The penetrant fills the surface discontinuities, and after a period of time the excess penetrant liquid is removed. Since water can not go into such tiny defects the penetrant in these places is not removed. When the part is watched in a dark room with the help of a special light of UV, the penetrant becomes visible since it is a fluorescent liquid, and cracs, laps, seams, lack of bonding, pinholes, gouges, and tool marks can be detected easily.
3.8 Composite and Metal Bonding (CAMB) : Many of our modern technologies require materials with unusual combinations of properties that can not be met by the conventional metal alloys, ceramics, and polymeric materials. This is especially true for materials that are needed for aerospace, underwater, and transportation applications. Aircraft engineers are increasingly searching for structural materials that have low densities, are strong, abrasion and impact resistant, and are not easily corroded. TAI, in order to compete with the big companies of the world had to have a composite and metal bonding department. TAI CAMB department covers an area of 9450 square meters under roof. Material property combinations and ranges have been, and yet being extended by the development of composite materials. Generally, speaking, a composite material is considered to be any multiphase material that exhibits a significant properties of both constituent phases such that a better combination of properties is realized. According to this principle of combined action, better property combinations are fashioned by the judicious combination of two or more distinct materials. The equipment used in CAMB area are as follows :
34
The Freezer : The composite materials are kept in the freezer at -18 C. They have to be used in 10 hours after getting out of the freezer. Thermal Equipment Corp. Autoclave: Diameter : 141.73’’ Length : 551.18’’ Operating pressure : 250 psi. Operating temperature : 400 2 C Heating, cooling rate : 0 - 5.5 C/min The parts that have been formed before and the sandwich panels first pass through a prefit operation, than the surface of the metal workpiece is cleaned by chemical means. With the aid of anodizing the surface quality of the part improves. Than the parts go to the clean room in which the temperature, humidity, and dust values are controlled carefully. This is a 38304 m room. The temperature inside the room is 21 C, and the humidity is 45 %, and the maximum diameter of the dust is kept not greater than 10 m. The autoclave is used for heating the composite or metal bonding workpieces which are not very thick and/or not bond with honeycomb. Also it keeps the parts under pressure until the bonding is finished. Sitem Teknik Cure Oven : Length : 472.44’’ , Width : 157.48’’ , Height : 98.42’’ Operating temperature : 375 3 C Heating, cooling rate : 1 - 5 C/min Relatively thick composite or metal bonding parts and the ones that contain honeycomb are heated and kept under pressure till the bonding process is finished. Investronica CNC Ply Cutter Machine : Length : 283.46’’ , Width : 70.86’’ The ply cutter is used to cut composite parts which come from the refrigerator. The nesting system is used also with the aid of a computer connected to the cutter, so minimum amount of material is used, and material waste is degreased. Flow Abrasive Water Jet Cutting Machine : Length : 173.22’’ , Width : 106.3’’ , Height : 39.37’’
35
The machine uses a high-velocity fluid jet (Mach 2) impinging the workpiece, performing a slitting operation. A long-chain polymer may be added to the water of the jet to make the jet coherent, so that the jet does not come out of the nozzle as a mist. The majority of the metal working applications require the addition of an abrasive to the waterjet stream. The machine is especially used for cutting composite materials. The surface finish is reasonably good. Tecal Automated Ultrasonic Squirter System : The machine is for inspecting the bondings if there is any gaps inside with the scan rate being 500 mm/sec. Altinkaya Core Milling Machine : Length : 137.8’’ , Width : 59’’ , Height : 157.48’’ The machine is used to mill the core structure. If the core is thick enough, milling can be done before the bonding operations. But when the core is thin, the machine damages the core. Thin cores are first bonded with the composite structures and than milled. This way no damage is done on the workpiece. There are also 11 aluminum dipping tanks in CAMB department. These are : 1. Vapor degrease tank : The workpieces are degreased with trichloroethylene vapor at 91 C. 2. Alkaline clean tank : The workpieces are cleaned by very little material removal. 3. Deionized water rinse tank : The water is at 45 C max. 4. Acid brighten tank : Nitric acid, chromic acid, and hydrofluoric acid mixture at ambient temperature is used to clean the surface of F-16 parts. 5. Deionized water rinse tank : The water is at ambient temperature. 6. Deoxidizing tank : Sodium dichromate, sulfuric acid, and aluminum mixture at 60-77 C is used for cleaning the surface, and activating it by ion exchanges. 7. Deionized water rinse tank : The water is at 35 C. 8. Phosphoric acid anodize tank : The temperature in the tank is between 25-27C.
36
9. Deionized water rinse tank : The water is at ambient temperature. The remains of chemicals is cleaned. 10. Chromic acid anodize tank : Chromic acid anodizing at 33.5-36.5 C is performed in this tank. 11. Deionized water rinse tank : Water at ambient temperature. 12. Seal tank : Sodium dichromate at 95-100 C seals the tiny holes and the defects on the workpiece. There is also a drying oven operating at 60-90 C in the CAMB department.
3.9 Metallurgical Processing : There are four basic metallurgical processes performed in TAI. These are : Solution Heat Treatment Stress Relieving Annealing Artificial Aging The equipment used are : Drop Bottom Quench Furnace : Work space : L=6.2m , W=1.2m , H=1.9m Max. load capacity : 1000 kg Max. operating temperature : 593 C Temperature uniformity : +5 C The furnace is used for precipitation hardening of aluminum and its alloys. The aluminum alloys of any phase are first heated to certain temperatures and than quenched in to water. Aluminum, after quenched, is in W phase which is relatively soft and machinable. All aluminum raw materials after quenching are put in to a large walk in refrigerator. The temperature inside the refrigerator is approximately -23C. The aluminum workpieces are kept maximum 3 days in the refrigerator. The material has to be machined not later than 3 days. Aging occurs and aluminum change phase after 3 days even if it is kept in the refrigerator. There is also another consideration in machining
37
aluminum that it has to be machined in half an hour after being taken out of the refrigerator. Because the process is a little bit complicated, production planning becomes very important. The worker has to be waiting for the raw aluminum taken out of the refrigerator in his task center, so that there will be no need for a second heat treatment operation. That can mean a lot of waste of time, and ofcourse money. Aluminum Age Oven : Work space : L=6.1m , W=2.4m , H=3.0m Max. load capacity : 900 kg Max. operating temperature : 260 C This oven is used for secondary heat treatment of aluminum alloys. Artificial aging is done. Grit Blast Steel Treatment Oven : Max. operating temperature : 1000 C This oven is used in heat treatment of small steel alloys. Full annealing, annealing, and quenching operations are performed. The oven is also used in stress relieving operations.
3.10 Explanation of the Production Stages of Sample Products : Sample 1. The sample is an aluminum alloy fitting that is to be used in CN-235 CASA aircraft. the technical drawing of sample 1 is available in *appendix 2. The material ( L-3140 - T351 ) is taken from the material depot than inspected for its material properties in the material inspection unit in first cut area. The conductivity, thickness, and hardness of the material is measured. After the inspection the material is saw in multiples per SOIR in the plate saw. Than the multiples are again saw to the rough size in the band saw.
38
With all these operations done, the multiples left the first cut area and taken to the conventional machining area. The materials are milled in the universal milling machine through adjacent surfaces with minimum clean-up. Than the 86 mm, 17mm, and 30mm dimensions are created. The R12, and the R8 dimensions are also done by universal milling machines. 76.4mm and the 5mm thickness and also the 745 chamfers are done. The material than went to the boring machining area. The 9mm dia. holes and 0.545 in two places are drilled and reamed. After the drilling and reaming operations, deburring and hand finishing is done. The part is than inspected in the conventional machining inspection unit for the dimensional requirements of the drawing. Also, conductivity, surface roughness, surface integrity, and surface quality tests are done. The part than went to vapor degreaser and degreased. Penetrant inspection is done after vapor degreasing in the chemical processing area. The part is wanted to be chromic acid anodized so this process is applied, and rubber stamp part number is stuck. After anodizing the part is again inspected in chromic acid anodize inspection unit. In this inspection, the part is examined whether the coating is smooth, adherent, and free from embedded foreign material, powdery areas, loose film, breaks, arc burns, scratches, nitric acid erosion and corrosion. After inspection, the 9mm dia holes are masked in priming and painting applications unit. The parts then are taken to the stock after manufacturing operations are finished.
Cost calculation of sample 1. : General and Administrative rate : 2$ per direct labor hour. Manufacturing Rate : 3$ per direct labor hour. Material Cost : 0.4$ per cubic centimeter. Labor Rate : 1.875$ per hour. Direct labor hours for sample 1. is 175 min. Direct Labor Price : 1.875 ($/hr) (175/60) (hr) = 5.468$ Direct Material Cost : (456090) cubic millimeters 0.4 ($/cubic centimeters) = 97.2 $ General & Administrative : 3 ($/DLH) (175/60) (hr) = 8.75 $ Manufacturing Prize : 2 ($/DLH) (175/60) (hr) = 5.83 $ Total Cost : 117.248 $
Sample 2.
39
Sample 2 is an aluminum alloy fitting that is to be used in CN-325 CASA aircraft. The technical drawing of sample 2 is available in *appendix 3. The material to be used in manufacturing of this fitting is L 3710 T 7351 aluminum alloy. The raw material is taken out of the material depot to the first cut area. The first inspection of the material is done in first cut inspection unit, for its thickness, heat number, and hardness. The material then saw in multiples per SOIR with the plate saw, and then saw to rough size with the band saw. After the operations done in the first cut area, the material is taken to the machining area for the milling operations. The adjacent surfaces are milled with minimum clean-up, and then the cutouts, the channel of 15mm, and the 76.585mm dimensions are milled with the universal milling machine. The 25.5mm, 64.4mm dimensions with R9 is milled with Hitachi Machining Center. In the boring machining area the 10mm dia. hole and the 0.545 chamfer is drilled, reamed and honed. Deburring of the part is done with the hand finish where required to blend all mismatch surfaces. The part then went to the conventional machining inspection unit to be inspected for its conductivity, heat treat condition. After the previous inspection the surface roughness, surface integrity, and surface quality is also inspected. The part is degreased in the vapor degreaser and taken to the chemical processing area. Penetrant inspection is done. Chromic acid anodizing is applied and also chemical film is brushed to the electric contact points. For the verification of the chemical treatments, the part is inspected in the chromic acid anodizing inspection unit, the criteria being ; coating shall be smooth, adherent, free from embedded foreing material, powdery areas, loose film, break arc burns, scratches, nitric acid erosion and corrosion. Primer coat is applied on the surface. After the last inspection, the part number is rubber stamped to the part and the part carried to the stock.
Cost calculation of sample 2. : General and Administrative rate : 2$ per direct labor hour. Manufacturing Rate : 3$ per direct labor hour. Material Cost : 0.4$ per cubic centimeter. Labor Rate : 1.875$ per hour. Direct labor hours for sample 2. is 150 min.
40
Direct Labor Price : 1.875 ($/hr) (150/60) (hr) = 4.6875$ Direct Material Cost : (853670) cubic millimeters 0.4 ($/cubic centimeters) = 214.2 $ General & Administrative : 3 ($/DLH) (150/60) (hr) = 7.5 $ Manufacturing Prize : 2 ($/DLH) (150/60) (hr) = 5 $ Total Cost : 231.3875 $
Sample 3. The sample is a L-3767 -T7451 aluminum alloy support that is to be used in a CN235 CASA aircraft. The technical drawing of sample part 3 is available in *appendix 4. The raw material is taken out od the material stock and inspected for its heat number, thickness, and hardness. The material is first saw in multiples with the plate saw, then saw to rough size with the band saw in the first cut area and after that went forward to conventional machining area. The adjacent surfaces are milled with minimum clean-up. Then one of the side cutouts is milled to hold 2.5mm thickness as well as the contour. Top view cutouts and 37mm radius arc is milled. The operations up to now is performed with the Hitachi machining center. The 5mm dia. holes are drilled in the boring area, and then hand finishing is applied to blend all mismatch surfaces and radii. After the inspection for the heat treatment condition, conductivity, surface roughness, surface integrity, and surface quality, the part is vapor degreased. Penetrant inspection is done and then chromic acid anodizing is applied. Electric contact surfaces are brushed with chem. film. After the chemical processes the part is inspected again. The part is rubber stamped and taken to the stock.
Sample 4. Sample 4 is a L-3140-T3511 aluminum alloy support that is to be used in CN-235 CASA aircraft. The technical drawing of the part is available in *appendix5. The raw material is inspected for its heat number, thickness, conductivity and hardness in the first cut inspection unit. Then the material is saw in multiple length as
41
required per shop order with excess allowance for chucking, cutting off, and facing each separate part. The material is milled to hold (19+10)10mm, and then rotated 90 to keep (41+8)mm and (8+20+11+8)mm dimensions with the universal milling machine. The R8 and the two 2.5mm dia. holes are drilled with radial drilling machine. After deburring, the part is inspected for ; i. Dimensional requirements per drawing ii. Surface roughness per drawing iii. Surface integrity (visual evidence of overheating, smearing, galling, or contamination.) iv. Surface quality (scratches, nicks, gouges etc.) Penetrant inspection is performed on the part in the chemical processing area. Chromic acid anodizing is applied on all the surfaces of the part. Chemical film is brushed on the contact points. In the inspection of these chemical treatments, the part is examined that the coating should be smooth, adherent, free from embedded foreing material, powdery areas, loose film, break arc burns, scratches, nitric acid erosion and corrosion. The part is rubber stamped and carried forward to the stock.
Sample 5. The L-3710-T7351 aluminum alloy part is being used in a CN-235 CASA aircraft. The technical drawing of the part is available in *appendix 6. The operation sequence of the part is not different from the ones above. The material is inspected (heat number, raw material dimensions, conductivity, and hardness.), and saw first in multiples per SOIR and then to the rough size in the first cut area. In the machining area the material is milled to hold 35mm dim. and the chamfers 5 45 and 2.545 in the universal milling machine. The pockets are milled as well as the R8 corners. Also the R10 & R14 dimensions are milled. The 14mm diameter hole and chamfer is drilled, reamed and honed. After deburring, hand finish is applied to the part to blend all mismatches surfaces and radii. The operations performed on the part is inspected in the conventional machining inspection unit.
42
The part is vapor degreased and penetrant inspected in the chemical processing department. Chromic acid anodizing is applied on all surfaces of the part. Chem. film is brushed to the unanodized contactmarks. After the last inspection, the part is rubber stamped and carried forward to the stock.
IV. CONCLUSION TAI is a big company challenging with the other aircraft industries all over the world. The quality control operations are very well organized that the product is nearly perfect and respected. All the employees are well educated in their fields either in Turkey or in USA. TAI Training Center provides technical training to develop their skills and knowledge required to perform the special tasks directly related to the production. But there are also some problems in the company as well. One of the biggest problem is the need for new projects. All the things to be done is in the final stages of completion. Since the company and the employees have become proficient in aerospace manufacture, there should be no difficulty in finding new projects. Since the projects are near completion, the efficiency is low compare to the one in the beginning stages of the production. The employees have lost their excitement to work. This increases the percentage of the scrap material, and the time required for production. There is almost two man to do one piece of work. This causes money loss in great deals.
43
The aircraft industry is developing very fast and TAI also has to improve itself and must give much more importance to research & development activities to stay competitive, profitable and healthy in today’s world market place. There is no explanation for buying the things that we can manufacture by ourselves. This can be nonprofitable in the early times but it is for sure that it will be profitable in the future. It is quite for sure that this summer practice was very useful for the mechanical engineering students, and I believe TAI is one of the few places that gives the opportunity to examine the production techniques, the machines, the products manufactured, and the systems operating.