Mechanical parts mainly include metal parts materials and non-metal materials:
A Metal materials
1. Cast iron
Cast iron and steel are both iron-carbon alloys. The difference between them is mainly in the carbon content. Iron-carbon alloys with a carbon content of less than 2% are called steels, and those with a carbon content of more than 2% are called cast irons.
2. Steel
Compared with cast iron, steel has high strength, toughness, and plasticity, and its mechanical properties and processing properties can be improved by heat treatment. The blanks of steel parts can be obtained by forging, stamping, welding or casting, so they are widely used. According to the application, steel can be divided into structural steel, tool steel, and special steel.
1) The carbon content of carbon structural steel is generally not more than 0.7%. Low carbon steel with a carbon content of less than 0.25% has a low strength limit and yield limit, high plasticity, and good weldability. It is suitable for stamping and welding. It is often used to make screws, nuts, washers, shafts, Valve guides, and welded components, etc.
2) Alloy structural steel
The effect of adding alloying elements to steel is to improve the properties of steel.
3) Cast steel
The liquid fluidity of cast steel is worse than that of cast iron, so when casting with ordinary sand, the wall thickness is often not less than 10mm. The shrinkage rate of steel castings is larger than that of iron castings, so the rounded corners and transition parts of different wall thicknesses of steel castings should be larger than those of iron castings.
3. Copper alloy
Copper alloy is divided into bronze and brass. Brass is an alloy of copper and zinc and contains a small amount of manganese, aluminum, nickel, etc. It has good plasticity and fluidity, so it can be rolled and cast.
B Non-metallic materials
1. Rubber
Rubber is rich in elasticity and can absorb more impact energy. Ebony can be used to make bearing bushings lubricated with water.
2. Plastic
The specific gravity of plastic is small, and it is easy to make parts with complex shapes, and various plastics have different characteristics, such as corrosion resistance, heat insulation, insulation, friction reduction, and large friction coefficient. Its application is increasingly widespread.