The FMA Forecast And Experiment Research Of Advanced Ceramics Surface And Sub-surface After Grinding

Ceramic grinding induces residual stress, which can play an important role on the fatigue, fracture strength, surface hardness and wear resistance of the component, and it is one of the important reasons to bring cracks. In this paper surface and sub-surface residual stresses of ceramics had been studied systematically. The residual stresses were calculated via FMA using the thermoelasticity-plasticity theory, which is an effectual and convenient method to predict and control the residual stresses.Firstly, the two causing residual stresses factors have been systematically researched, and the grinding forces and temperature experiments of two ceramic materials had been done, the force and temperature experiential formulas of Si3N4 and ZrO₂ were gained. Secondly, the grinding process was simulated by FMA, taking the result of force and temperature as the loads, the residual stresses were calculated, the dynamic simulation of the ceramic grinding was accomplished through the loads moving along the marterial surface, and then the residual stress field of the ceramic material was known. Thirdly the grinding residual stresses of ZrO₂ and Si3N4 ceramics were measured by experiment method. Using the penetrable ability of X-ray, the residual stress distributing values on the subsurfaces were measured. Lastly, compared with the two kinds of methods, the Si3N4 ceramics residual stresses value of the simulation by FMA is satisfactory.In addition, the differences and resemblances of the residual stresses between ceramic and metal were analyzed, and present the origin mechanism and characteristic of the grinding.ceramic residual stresses had been discussed.