Rolling wear of silicon nitride bearing material in a simulated refrigerant environment using a novel pressurized chamber

摘要

The core emphasis behind this research was to analyse the erosion wear of rolling hybrid ceramic (Si_3N_4) bearing material in Hydrocarbon (HC), Hydrofluorocarbon (HFC) and simulated refrigerant (petroleum ether and kerosene oil) environments. A novel pressurised chamber was designed to achieve a liquid state of the refrigerant as fluid for the rolling contact fatigue experiments. Design of the pressurised chamber is described in this paper. A cooling system was used to control the temperature and pressure of the pressurised chamber. The High Speed four ball Rotary Plint Tribometer was used for rolling contact fatigue tests. This paper presents an experimental study of the influence of the HC (R600a) and HFC (R134a) environment on rolling wear of the silicon nitride/steel elements. Rolling fatigue test methods were used to measure the wear performance of silicon nitride/steel bearing materials. Light microscopy was used to examine the material surface before carrying the tests. Light microscopy was employed for surface examination during and after tests. Wear of rolling Si_3N_4 was measured in R600a and R134a refrigerants. Failure modes and rolling wear performance for these ceramic materials in both environments were compared. Investigations of lubricated contact of Si_3N_4 reveal that wear rate is affected by the environments. Schematic drawings of these wear processes and experimental results are presented in this paper.