Surface textures can increase the lubricant film pressure and lubricant film thickness to reduce surface contact between bearing surfaces. We are solving fluid dynamics equations to find the optimum texture design parameters that will maximize the lubricant film thickness of bearing surfaces under different loads and operating conditions. This allows us to customize bearing surfaces for specific applications by designing the texture patterns.
Ceramics are good materials for bearing surfaces, including orthopedic implants, because of their high hardness and electrochemical inertness. These properties also make them extremely difficult to machine. We are studying advanced precision manufacturing methods such as laser machining and electric discharge machining (EDM) for these ceramic materials. We quantify the material removal, accuracy, and effect on microstructures and material properties to optimize the manufacturing processes.
Cobalt-chromium-molybdenum (CoCrMo) alloys are common biomaterials for orthopedic implants because of their biocompatibility and resistance to wear and corrosion. We are studying the effects of different heat treatments on the microstructures of the CoCrMo alloys and performing long-duration wear tests with conditions that mimic those of a prosthetic joint implant, including dynamic loading cycles and bovine serum lubrication. We also monitor the corrosion activity and any changes in microstructure throughout the wear tests. We aim to identify the material processing techniques that will maximize the wear and corrosion resistance of the CoCrMo biomaterials.