Gives Comprehensive info about sand castingFull description
Full description
A laboratory report for a sand casting experimentDescripción completa
Lab Report Die Casting AssignmentFull description
Full description
Laporan Praktikum IMKG
imkg praktikum
GeoFoamFull description
Full description
Deskripsi lengkap
Slip casting of white ware body (Ceramics) This is the simplest method of shaping Hollow articles in ceramics, specially used for making bonechina wares, tablewares and sanitary wares etc.Full description
Information about Centrifugal Casting.
INTRODUCTION The Lost Foam casting process originated in 1958 when H.F. H.F. Shroye Shroyerr was grante granted d a patent patent for a cavity cavity-le -less ss castin casting g metho method d !sing !sing a polyst polystyr yrene ene foam foam patter pattern n em"ed em"edded ded in tradi traditio tional nal green green sand. The po!red molten metal decomposes the polystyrene foam patt patter ern n left left in the the sand sand.. The The meta metall repla eplace ces s the the foam foam patt patter ern n e#actly d!plicating all of the feat!res of the original pattern. Li$e other casting methods this re%!ires that a pattern "e prod!ced for ever every y cast castin ing g po!r po!red ed "eca "eca!s !se e it is evap evapor orat ated ed &'lo &'lost st() () in the the process. *ene *enera rall lly y all all fer ferro!s o!s and and nonnon-fe ferrro!s o!s mater ateria ials ls can can "e s!ccessf!lly cast !sing the Lost Foam process. +eca!se the foam patt patter ern n and and gati gating ng sy syst stem em m!st m!st "e deco decomp mpos osed ed to prod prod!c !ce e a castin casting g metal metal po!rin po!ring g temper temperat! at!re res s a"ove a"ove 1,,,F 1,,,F are are !s!all !s!ally y re%!ired. Lower temperat!re metals can "e po!red "!t part sie is limited. /n addition very low car"on ferro!s castings will re%!ire special processing. processing. Lost Foam castings can "e prod!ced in most all metals from a frac fractio tion n of a po!n po!nd d !p to tho! tho!sa sand nds s of po!n po!nds ds.. Slig Slight htly ly mor more advanced techni%!es are !sed for very large castings. The e#penda"le-pattern e#penda"le-pattern casting process !ses a polystyrene polystyrene pattern which evaporates !pon contact with molten metal to form a cavity for the casting. The process is also $nown as evaporativepattern or lost-pattern casting and !nder the trade name F!ll-0old proc proces ess. s. /t was was for formerl merly y $now $nown n as the the 'e#p 'e#pan ande ded d poly polyst styr yren ene e proc proces ess( s( and and has has "eco "ecome me one one of the the mor more impo import rtan antt cast castin ing g proce processe sses s for ferro ferro!s !s and nonfer nonferro ro!s !s metals metals partic partic!la !larly rly for the a!tomotive ind!stry. The evaporative-pattern evaporative-pattern process has has a n!m"er of advantages advantages over casting methods 1. The process process is relativ relatively ely simple simple "eca!se "eca!se there there are no parting parting lines cores or riser systems2 hence it has design 3e#i"ility. 4. /ne#pensi /ne#pensive ve 3as$s 3as$s are are s!cient s!cient for the the process. process. 6. 7olystyr 7olystyrene ene is ine#pensiv ine#pensive e and can "e easily processed processed into into patterns having comple# shapes vario!s sies and ne s!rface details. . The casting casting re%!ir re%!ires es minim!m minim!m nishin nishing g and cleaning cleaning operations 5. The process process can can "e a!tomated a!tomated and and is economic economical al for long long prod!ction r!ns. : ma;or factor is the cost to prod!ce the die !sed for long prod!ction r!ns. : ma;or factor is the cost to prod!ce the die !sed for e#panding the polystyrene "eads to ma$e the pattern.
Typical applications for this process are cylinder heads cran$shafts "ra$e components and manifolds for a!tomo"iles and machine "ases. :l!min!m engine "loc$s and other components for *eneral 0otors Sat!rn a!tomo"iles are made "y this process. !ring the process of molding the polymer pattern "ers or particles are em"edded thro!gho!t. These "ecome an integral part of casting. F!rther techni%!es incl!de modication and grain renement of the casting "y the !se of grain reners and modier master alloys within the pattern while it is "eing molded
SAFETY PRECAUTIONS:
• • •
• •
•
•
?ear safety shoes if heavy wor$ is "eing done. ?ear clothing s!ited for the ;o" wear shoes with thic$ soles. >o not wear rings watches "racelets or other ;ewelry that co!ld get co!ld get ca!ght in moving machinery. >o not wear nec$ties or loose t!rn clothing of any $ind. ?ear shirts or !ppers with sleeves c!t o@ or rolled a"ove the el"ows. /f material is ro!gh and sharp then gloves m!st "e wor$ place or handle material. ?ear leather glove apron and face shield d!ring po!r molten metal
WORKING PROCEDURE 1. The Styrofoam patterns is made "y !sing polystyrene 4. The parts of foam patterns is gl!ed together along with spr!eA r!nnerA ingate as re%!ired 6. The pattern is placed in silica sand ta$ing care to compact the sand a"o!t the pattern . 0olten metal &al!min!m) is casted into the pattern. The foam is evaporated and escaped thro!gh the normal ro!tes gas evac!ates thro!gh 5. :fter that the part is left !ntil its cool down and solidied B. :fter it f!lly solidied the sand is removed. Then the prod!ct is "een ta$en o!t from the sand. C. The prod!ct is o"served for any casting defects.
RESULTS AND DISCUSSION >!ring lost foam casting method is carried o!t there are n!mero!s defects have "een identied .The defects will "e disc!ssed and co!ntermeas!res or remedies was ta$en to overcome defects in foam casting.
Porosity 7orosity is tho!ght to "e severe in al!min!m alloy castings prod!ced "y lost foam process d!e to the pyrolysis of the polystyrene foam pattern d!ring po!ring which res!lts in detrimental e@ect in mechanical property. The slow solidication rate promotes the formation of gassing pin holes and relative wea$ness of the thermal gradients can ca!se micro-shrin$age if the o!tline of the part complicates feeding in the lost foam casting. Do!ntermeas!res •
•
Ene of the methods to eliminate the porosity is to apply high press!re to the molten metal li$e an isostatic forging d!ring solidication :pplying e#ternal press!re was e@ective in decreasing the porosity and increasing the elongation of the lost foam casting.
Sand Inclsion Sand incl!sion is also called as sand hole which is $ind of metal casting defect. /t loo$s li$e small or middle holes with a sand grain in the internal or on the s!rface of casting. If the sand molds or cores have been overbanked, then their surfaces will become more fragile because the adhesive will lose its stickiness, which will cause some sand inclusion defects. Countermeasures •
0etal ll gl!e ll agent 0etal-lled gl!e contain %!art and metal components so casting s!rface after lled "y this gl!e will have a certain hardness and it can stand f!rther machining process and a temperat!re of 145 to 4,, Delsi!s degree.
•
lectrical welding ?elding is !sed for repairing middle or large sand incl!sion. :fter welding the positions with sand holes will still $eep good strength and can stand the high temperat!re as metal.
!isrns /ncompletely formed casting d!e to premat!re solidication of metal "efore the mold is lled. ?hen the metal is !na"le to ll the mold cavity completely and th!s leaving !nlled portion called misr!n. : cold sh!nt is called when two metal streams does not f!se together properly. Do!ntermeas!res • • •
:d;!st proper po!ring temperat!re 0odify design 0odify gating system
CONCLUSION The casting seems li$e very easy. +!t it is dic!lt to ma$e. very step is interconnected with other process. /f any process has not "een completed well it will lead to !n%!alied casting. Therefore for the newly p!rchased lost foam prod!ction line enterprise the good training and reasona"le management systems are very important. So we can !se this casting process to contri"!te innovative ideas for prod!cing fo!ndry prod!ct and a!tomation sol!tion that meet mar$et environment.
