Table of Contents
What are non-metallic materials?
Non-metallic materials are those materials which lack metallic attributes (lustrous, malleable, ductile, good conductors of heat and electricity etc.). They are generally used in engineering due to their flexibility, low cost and resistance to heat and electricity.
Following are some important non-metallic materials used in the design of machine elements.
Gears made from plastic
Plastics
Plastics are synthetic materials which can be moulded into desired shapes under pressure (with or without the application of heat).
Plastics are extensively used in various industrial applications because o their corrosion resistance, relatively low cost and dimensional stability.
Following are two main types of plastics
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Thermosetting plastic
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Thermoplastic
Thermosetting plastic is a polymer that irreversibly becomes rigid when heated.
Thermoplastic is a polymer, which becomes soft when heated and hard when cooled.
Rubber
Rubber has high bulk modulus.
Rubber is used in drive elements, vibration isolation, sealing and similar applications.
Leather
Leather is used in engineering due to its wear resistance and flexibility.
Rubber is used in making washers and belt drives.
Timber
Timber is relatively low-cost material. It is bad conductor of both heat and electricity. It has good elastic and frictional properties.
Timber is widely used in making foundry patterns and temporary machine parts (like wheels, gears, shafts etc.).
Featured image source: By Hustvedt – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5743822