Investigation of the grinding temperature and subsurface quality of a novel point grinding wheel

Abstract

In this paper, a novel point grinding wheel (NPGW) with coarse grinding area angle θ is proposed. According to earlier studies, this type of grinding wheel has the advantages of high grinding efficiency, a long service life, and very little surface roughness generated. The contact zone between the grinding wheel and workpiece is modified by the addition of the NPGW with the coarse grinding area angle θ and the inclining angle α of the point grinding process, and as a result, the grinding zone temperature is also altered. Using the finite element method, the grinding zone temperature can be simulated based on the theory of grinding heat generation and distribution, and the triangular heat source distribution model. From this, the distribution of the point grinding temperature field and influence of different grinding parameters on the grinding zone temperature were obtained. To verify the simulation, thermocouple measurements for different NPGWs were taken during the grinding experiments. The simulation provides an auxiliary and predictive method for the actual process. Moreover, an L16(45) orthogonal experiment was designed. Analyzing this range, primary and secondary factors affecting grinding zone temperature, and the optimum combination of parameters for reducing the grinding zone temperature, are determined. Finally, the grinding heat can affect the quality of the workpiece subsurface; therefore, the influence of the various parameters on subsurface quality, including metallographic structure, work hardening, and residual stress, was studied. In conclusion, the NPGW and point grinding process can reduce the degree of work hardening and residual stress of the subsurface of the workpiece, and it was demonstrated that the residual stress changes from compressive to tensile with increasing depth.