Selection of Materials based on Mechanical Properties | How to do a Material Selection

Selection of Materials based on Mechanical Properties

Selection of Materials based on mechanical properties for a design has a very important component in Machine design. When put into service, different machine elements face different working conditions, which hey have to survive. This, in turn depends on the material by which they are made. Hence we say that a correct choice of material determines the working of any machine component.

Typical Mechanical Properties and applications are:

1. Strength:

Steel with Alloying elements such as

1. Nickel steel – Turbine Blades. Nuts, Screws
2. Nickel Chromium Steel or Stainless Steels – Aircraft component, Gear with Heavy loads
3. Chromium Molybdenum Steels – Gear box shafts, Gears
4. Silicon – Manganese Steel – Axles, Shafts
   

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 2. Hardness:

1. Alloy steel – Gears, Chain sprockets Bearings, Bushes cutting tools, Grade 400 – 500 cutting tools
2. Stellite – Cutting tools for Surgeons
3. Ceramics – Cutting tools, Refracting Linings
   

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3. Ductility:

1. Steel – Thin wires, Rods
2. Copper – Thin wires, Rods
3. Aluminium – Thin Wires, Rods
4. Silver – Thin Wires, Rods
   

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4. Malleability:

1. Aluminium – Sheets
2. Galvanized Iron – Sheets
   

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5. Toughness:

1. Titanium – Aircraft parts, Machine tools, Connecting rod valves
   

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6. Machinability:

1. Cast iron – Bed-ways of Machine tools, Frames, Piston Rings, Brake Drums, Flywheels, gears
   

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ALLOYS

Often, a material cannot possess all the required qualities. Some materials are added together in certain proportions to achieve the collective goodness of them. The resulting composition is called as Alloys.

Some important alloys and their typical uses are given below:

1. Steel based Alloys:

1. Nickel steel – Turbine Blades. Nuts, Screws
2. Nickel Chromium Steel or Stainless Steels – Aircraft component, Gear with Heavy loads
3. Chromium Molybdenum Steels – Gear box shafts, Gears
4. Silicon – Manganese Steel – Axles, Shafts
   

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