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 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.

Gearlike cylindrical structure can be used as outer ring of linear bearing for saving material, but the machined surface quality and roundness of this kind of bearing is beyond control in cylindrical grinding and machining efficiency is low. To solve these problems, a new method of pre-stress grinding for gearlike cylindrical surface of linear bearing is put forward based on analysis on the principle of cylindrical centerless grinding. For implementing this process, a set of device with expanding mandrel for loading tensile pre-stress on bearing ring is designed and experiment of through-feed grinding is carried out on centerless grinder. The experimental results show that this method can get fine quality of machined surface and increase the grinding efficiency greatly.

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.