Hard And Brittle Materials, Abrasive Belt Grinding

Hard-brittle materials are widely used due to their high hardness and brittleness. However, they are very difficult to machine with a result of poor machinability and high productive cost.Supported by National Natural Science Fund, in this thesis, studies were carried out into grinding technology and morphology simulation studies of belt grinding of hard-brittle materials, aiming at providing a new, economic and efficient machining method for grinding hard-brittle materials. Through belt grinding experiments of several typical hard-brittle materials, some important technological parameters were investigated, which affect the material removal rate and surface roughness, involving grinding method, materials and abrasive grits of belt, workpieces materials, moving patterns and coolants, etc. Considering the brittle-crack characteristics of hard-brittle materials, simulation model of surface appearance of grinding hard-brittle materials was setup.The experimental results indicate that higher material removal rate and lower surface roughness can be obtained in belt grinding through proper selection of machining techniques according to different workpiece materials. Roughing and semi-finishing can be completed at the same time, which leads to hard-brittle materials machining with high quality and efficiency.The grit shape, brittle-crack characteristics of hard-brittle materials and table moving patterns, etc. were considered in simulation models. Simulation results, which adopt grit of elliptical cone and consider the crack characteristics of brittle materials, accord well with the experimental results. The simulation program can rapidly forecast grinding results optimize technical parameters without actual system, and will be instructive to the actual production.