Ceramic Coated Bearing Elements for Improved Durability and Reliability

摘要

BIRL, of Northwestern University, conducted research in the application of hard,wear resistant coatings onto bearing steels and silicon nitride. These coatings were deposited using the high rate reactive sputtering (HRRS) process. Prior to this work, the authors had demonstrated the ability to deposit hard coatings such as titanium nitride onto materials such as M2 tool steel, cemented carbide inserts, and hardened 440C steel without degradation of the metallurgical properties of the coated piece. In this program, it was shown that TiN coatings deposited onto test components, which simulate entire hybrid bearings, had extended the average rolling contact fatigue (RCF) lifetimes of the uncoated components by factors of at least 2.6 on average and as much as 4.6 for specific components when run under accelerated conditions. Since the M50 material failed in many of these tests, it is believed that non-accelerated tests would show even larger increases in RCF lifetime due to the coatings. Accelerated test results suggest the increases in RCF lifetime should be obtainable on real-life components coated with thin, hard materials.