Grease lubricated angular contact ball bearings are usually used in spindle bearings of high-speed machine tools. The large temperature increases during high-speed operation seriously affect the bearing precision, resulting in a loss of operating precision and reduced service lives. This study predicts the bearing loads with the influence of thermal deformation on the force equilibrium of angular contact ball bearings. The local heat generation rates are predicted with grease lubrication using a multi-node thermal network to model the angular contact ball bearings that predicts each node temperature. The results show the influence of the thermal deformation on the bearing temperature rise and the forces on the bearing with the simulation results verified through experiments. The predicted bearing outer ring temperatures based on the force balance calculation with the thermal deformation are in good agreement with experimental data with errors of less than 10% which verifies the reliability of this method for predicting the temperature rise of grease lubricated high-speed bearings.

Water is one of the most significant causes of lubrication failure. There is little research on the direct observation of the impact of water on lubrication properties. In this study, the influence of water on oil replenishment under different elastohydrodynamic (EHD) lubricating conditions is evaluated using optical interferometry and infrared microscopy, and a dimensionless criterion when water influences the film thickness is proposed. Evidence shows that the scour displacing effect and emulsification of water/oil are the main reasons for the reduction in film thickness. Once a water droplet enters an oil reservoir around the critical contact zone, it hardly moves away. This aggravates starvation, reduces the center film thickness of the contact, and leads to lubrication failure of the mechanical components.

Chemical mechanical polishing (CMP) is the most effective method for surface planarization in the semiconductor industry. Nanoparticles are significant for material removal and ultra-smooth surface formation. This research investigates the mechanical effects of the material removal in the CMP process. The various contact states of pad, individual particle, and wafer caused by the variations of working conditions and material properties are analyzed. Three different mechanical models for the material removal in the CMP process, i.e., abrasive wear, adhesive wear, and erosive wear are investigated, with a focus on the comparison of the results for different models. The conclusions and methods obtained could potentially contribute to the understanding and evaluation of the CMP process in further work.