| dc.description.abstract | Development of novel additives in lubricants is a promising approach for high performance and energy saving devices. Those include automotive, marine, and wind turbines. In a wind turbine, the unplanned break-down rate of bearings caused by improper lubricants is 40% ~50%. The objective of this research is to 1) develop novel nanomaterials as grease additives, and 2) obtain understanding in tribological performances of the same. The research focuses on zirconium phosphate and yttrium oxide nanoparticles as additives in grease. Experimental approach is used to investigate the effects of those nanomaterials on lubrication of grease. Experiments such as tribological experiments at room and elevated temperatures, galling resistance tests, and characterization of worn surfaces will be conducted. Characterization includes optical microscope, interferometer, and scanning electron microscope (SEM). Results showed that the addition of nanoparticles induced reduction of coefficient of friction. In addition, the wear rate of the test samples was reduced by adding nanoparticles.
This research investigates the effects of nanoparticles with unique shape and structure and develops understating in mechanisms. The research results will be beneficial to the application of lubricants for high performance and efficiency.
This thesis contains six chapters. Chapter I is the background information about tribology and materials needed to understand this research. Chapter II describes the motivation and objectives. Chapter III discusses the experimental procedures and materials used in this research. Chapter IV and V present and discuss the results obtained from yttrium oxide and zirconium phosphate, respectively. Chapter VI discusses the major conclusions obtained from the results and offers suggestions for future work. | en |
