Topic 1: Selection of Engineering Materials and Equipments
Materials Selection Criteria and Standards
UEMK1103 - Introduction to Chemical Process and Electrical System - Rev Jan 2015
Material Selection is Important! Besides than SOFTWARE ENGINEER, the designers of any products must involve in material selection.
Your Decision! So many materials! Too much information!
How do we decide?
How do we begin to choose?
Types of Materials •
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Metals Alloys Ceramics Polymers
METALS
a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity.
ALLOYS
An alloy is a mixture of metals or a mixture of a metal and another element.
Metals
Ferrous
Pure Ferrous Metals
Non Ferrous Pure Non Ferrous Metals
Ferrous Alloys
Non Ferrous Alloys
Copper
Alum.
Zinc
Tin
Brass
Bronze
Solder
Copper + Zinc
Copper + Tin
Lead + Tin
Steel Iron High Speed Steel High Speed Steel Cutting Tools
Lead
Silver
Gold
Mercury
Mercury is the only non ferrous metal that is liquid at room temperature.
Alloying.
Ferrous Metals / Alloys Ferrous metal is referring to iron (Fe). Ferrous alloys are consist mostly of iron and small amounts of other elements. These materials are prone to rusting if exposed to moisture. Ferrous metals / alloys can also be picked up by a magnet . The rusting and magnetic properties in ferrous metals are both down due to the iron. Typical examples include mild steel, cast iron and steel.
Rusting.
Magnetism.
Example: Stainless Steels
Type SS316 → 16% chromium, 10% nickel, and 2% molybdenum
Type SS304 → 18% chromium, 8% nickel, no molybdenum.
SS316L SS304L
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‘L’ → Low carbon content(regular max 0.08%) Maximum 0.03% carbon Avoid corrosion problem caused by welding Used in pharmaceutical and food industry.
Example: Cast Iron
Is a very strong metal when it is in compression and is also very brittle.
It consists of 93% iron and 4% carbon plus other elements.
Used as car brake discs, car cylinders, manhole covers etc.
Example: Mild Steel
Mild steel will rust quickly if it is in frequent contact with water.
Ductile and malleable.
Used as nuts and bolts, building girders, car bodies, gates etc
Non-ferrous Metals / Alloys Non-ferrous metals / alloys are metals /alloys that do not have any iron in them at all. This means that non-ferrous metals are not attracted to a magnet and they also do not rust in the same way when exposed to moisture. Typical Non-ferrous metals include copper, aluminium, tin and zinc.
Example: Aluminium
It is very light in weight. Used for saucepans, cooking foil, window frames, ladders, expensive bicycles.
Aluminium Extraction: Bauxite Mining
Bauxite mining in Kuantan, Pahang
(Source: Bernama / Astro Awani, Jan 12, 2016)
(Source: Sinarharian, Jan 6, 2016)
Message
It’s important to recycle thealuminium cans.
Example: Copper
It is a very good conductor of heat and electricity.
red / brown in colour
Used for plumbing, electric components, cookware and roof coverings
Heat Conductor
Electricity Conductor
Example: Solder
an alloy of Lead and Tin fusible metal alloy used to join together metal work pieces and having a lower melting point than the work pieces (200C).
Types of Materials - Ceramics
Made of nonmetallic (clay) and firing at a high temperature.
Types of Materials - Polymers
A polymer is a large molecule, or macromolecule, composed of many repeated subunits.
You will learn more in Polymer Science and Technology
Example: Polyvinyl Chloride (PVC)
Production of PVC
Applications: Piping & fittings, cables
Light, chemical resistant, durable (for cables), rust resistant, cheap. Can’t sustain under high temperature, non biodegradable
PVC fittings
PVC cables
Material Properties •
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Chemical Properties Physical Properties Mechanical Properties Dimensional Properties
CHEMICAL PROPERTIES
Compositions Crystal structure A crystal structure composes of a unit cell, a set of atoms arranged in a particular way; which is periodically repeated in three dimensions on a lattice. Corrosion resistance The ability of a substance (especially a metal) to withstand damage caused by oxidization or other chemical reactions. Reactivity The chemical reactions of two or more substances that interact with each other.
PHYSICAL PROPERTIES
Melting point Thermal conductivity The property of a material to conduct heat Electrical conductivity/resistivity Material's ability to conduct an electric current/opposes the flow of electric current Grain size Also known as particle size, refers to the diameter of individual grains of sediment. Porosity Also known as void fraction, a measure of the void (empty) spaces in a material. Color
MECHANICAL PROPERTIES
Tensile properties Indicate the response of a material when tension/force is being applied. Ductility The ability of a material to deform under tensile stress Compressive properti es The capacity of a material or structure to withstand loads tending to reduce size Fracture toughness The ability of a material containing a crack to resist fracture
MECHANICAL PROPERTIES
Hardness The resistant of solid matter to various kinds of permanent shape change Creep resistance
The ability to resist any kind of distortion when under a load over an extended period of time.
Fatigue The weakening of a material caused by repeatedly applied loads Reinforcement The process of strengthening or increasing the mechanical properties of a material.
DIMENSIONAL PROPERTIES
Available shapes
Available sizes Surface textures
Manufacturing tolerances (thickness, width, length, flatness…)
You will learn more in Material Science
Materials Selection What does it do? How does it do it? Where does it do it?
Who uses it? What should it cost?
Case Study
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Soft Drink Container
Provide leak free environment for storing liquid.
Comply with food standards & protect liquid from health hazards.
For fizzy drinks, withstand pressure. Brand image & identity
Easy to open
Easy to store & transport
Cheap for high volumes
Case Study
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Possible materials: Aluminium Glass Plastic Paper
Soft Drink Container
Key factors applied to material selection
Operating conditions.
Design life time.
Good market availability and documented fabrication and service performance. The number of different material types shall be minimized considering costs, interchangeability and availability of relevant spare parts. Philosophy applied for maintenance and degree of system redundancy. Environmental issues related to corrosion inhibition and other chemical treatments.
Engineering Codes and Standards
Code: A document which gives guidelines for design, construction and installation, which are converted into law. Standard: A document which gives sizes/ rating/ joining methods of components. Each country has its own Codes and Standards. Normally American National standards are most widely used all over the world and compliance with those requirements are accepted globally.
Major Organizations of Standards Countries
Organization
U.S.A.
ASME
TheAmericanSocietyof Mechanical Engineers
ASTM
The American Society for Testing and Materials
ANSI
The American National Standards Institute
United Kingdom
BSI
British Standards Institute
Germany
DIN
Deutsches InstituteNormung
France
AFNOR
AssociationFrancoise
Europe
CEN
EuropeCommunityof Standardization
Japan
JIS
Japanese IndustrialStandards
