Theoretical analysis and experiments on bearing race show that a suitable residual compressive stress on roll path of bearing race can prolong its contact fatigue life. However, residual tensile stress is often found on workpiece surface of bearing race. To actively control the residual stress state and improve fatigue life of bearing part, a new method of pre-stress hard cutting is applied. In this paper, the principle of pre-stress hard cutting for bearing race is introduced as well as the experiments on it. In the experiments, residual stress, hardness and roughness of machined surface are measured and analyzed. Moreover, micro-topography and texture characteristics of machined surface are investigated and experimental results are compared with that by grinding. It is found that we can get residual compressive stress and fine quality on machined surface of bearing race by pre-stress hard cutting and increase its productivity as well.

The analysis on load characteristics and stress state of bearing races shows that the roll path and outside layer of a bearing race are the main part to bear the load, and that residual tensile stress is often found on workpiece surface. For the purpose of improving residual stress state on machined surface of a bearing race, a method of pre-stress hard cutting is put forward. In this paper, the principle of pre-stress cutting is introduced, and method of loading stress on bearing races, together with the calculation for pre-stress, is analyzed. A set of device with expanding mandrel for realizing the process is designed too and an experiment of pre-stress cutting is carried out on a lathe with PCBN tool. The experimental results show that, by using this method, we can get residual compressive stress on machined surface layer of a bearing race and increase the quality and contact fatigue life of bearing.

In this article, the micro-topography and texture characteristics of machined surface under the condition of high speed cutting are analyzed based on experimental observation. The forming process of machined surface and cause of the appearance are also discussed. The experimental results show that furrow and ridges, surface white layer and molten metal daub by the feed motion of cutting tool are found on machined surface due to the effect of high cutting temperature and rotating of workpiece in high speed turning process.

SiC particle-reinforced aluminum matrix composites (SICp/Al) is a kind of hard to cut material with excellent physical and mechanical performances. In order to solve the problem of tool wear rapidly and bad of machined surface quality in cutting, a new type carbide tool with guiding and finishing land was designed by analyzing on the forming mechanism of machined surface and state of tool wear in this paper. Experimental results show that tool life and quality of machined surface are improved significantly by using this new type tool.

The problem for adjusting heating current in Electric Hot Machining is how to detect the change of cutting condition. In this paper, Cutting state resistance has been proposed as a state parameter for self-adjusting heating current in EHM. An investigation on the relationship between this parameter and cutting conditions has been carried out. The experimental results show that cutting state resistance can rapidly respond the change of cutting state and optimum control of heating current can be realized in electric hot machining by means of detecting this resistance.