Experimental research on the residual stress in the surface of silicon nitride ceramic balls

The influence of thermal stress produced in sintering and mechanical stress formed in the lapping process on the residual stress in the surface of silicon nitride ceramic balls is discussed in this paper. By measuring the specific volume, the distribution of residual stress was analyzed and calculated. Some experimental research on the influence of the lapping process on the residual stress in surface of the balls was conducted. The surface of silicon nitride ceramic balls presented residual compressive stress after sintering and residual tensile stress after lapping. In the lapping process, the abrasive particles were finer and the load acting on the lapped balls was larger, the amplitude of the residual tensile stress in the surface of the silicon nitride balls being greater.