Coupled Effects of Fractal Roughness and Self-Lubricating Composite Porosity on Lubrication and Wear

Abstract

The lubricant characteristics of porous self-lubricating composites with a realistic rough surface are incorporated into an improved elastohydrodynamic model. The evolved model demonstrates that the wear rate can be measured by examining the lubricant distribution at various fractal dimensions and porosities. The results show that the physical nature of the rough surface topography and the composite's physical properties must be understood, because the relative contact area is enlarged and friction forces are increased by the increase in the fractal dimension and the porosity. It is obvious that the method can significantly improve the lubricant properties to avoid wear by controlling these two coupled effects. The research also indicates that optimization of the design the microstructure of the porous self-lubricating composite should focus on the porosity based on the wear rather than the amount of lubricant.

KEY WORDS:

• Self-Lubricating Composites
• Partial EHL
• Roughness Effects
• Film Geometry in Hydrodynamics
• Unlubricated Wear

ACKNOWLEDGEMENT

The authors thank the National Natural Science Foundation of P.R. China for financial support (ID 51075311). Professor J. R. Barber of the University of Michigan is acknowledged for fruitful discussions during this study.

Review led by Dong Zhu