Essential Properties and Qualities of Bearing Metals
The selection of the type of bearing metals depends upon on the conditions under which the bearing used such as temperature, bearing pressure, type of lubrication, rubbing speed etc. However, they must possess some general qualities. The desired characteristics of bearing materials are listed below.
- It should have the ability to withstand bearing pressure.
- It should have sufficient endurance strength to avoid failure due to fluctuating load.
- Bearing material should not damage journal material by sticking and welding.
- Bearing material possess embeddability characteristics to avoid damaging of the journal by dust and dirt particles.
- The bearing material should be elastic enough to restore its original shape upon removal of load after some distortion.
- It must be wear resistant.
- Many types of liquids, cutting fluids and lubricating oils may get in contact with the bearing. So it should have good noncorrosive properties.
- Wettability - it should have an affinity towards the lubricating oil so that it can adhere, spread and make a lubricating film over bearing surface.
- Bearing material should possess low coefficient of friction.
- It can be easily manufactured, it should have good casting qualities.
- After casting, the shrinkage must be minimum.
- It can be operated at maximum rubbing speed with suitable lubrication.
- Bearing material exposed to heat, so it must have high thermal conductivity and high melting point. It should also have low thermal expansion.
- The material used for bearing should be economical. Low cost and easily available material.