晶须增韧陶瓷刀具材料的磨损机理

本文对SiC晶须增韧Al2O3陶瓷刀具材料的摩擦磨损特征和耐磨性能进行了试验及理论研究。用有限元法分析了SiC晶须在磨损过程中的力学特点，解释了晶须定向对不同表面的耐磨性能的影响。通过对x射线衍射极点密度的测试计算，发现基体Al2O3的晶体有择优取向的趋势，从而由晶体学角度分析并提出该现象对试件不同表面耐磨性能的差异也有一定影响。切削试验进一步验证了以上结论。本文提出应选用平行于热压轴方向的表面作为承受磨损的面。

WEAR BEHAVIOUR AND MECHANISM OF WHISKER REINFORCED CERAMIC TOOL MATERIAL

The effect of preferential alignment of SiC whiskers in Al2O3 matrix on wear behaviour has been studied by scanning electron microscope observation, tribe-physics, finite element method analysis and metal cutting tests. The SiC whisker reinforced Al2O3 ceramic specimen showed a discrepancy of wear performance on the planes in the directions perpendicular or parallel to the hot pressing axis. Experiments show the plane parallel to the hot pressing dirention was found to be significantly more wear resistant than the plane normal to the hot pressing direction. SEM examination revealed that the oxidated SiC whiskers prior were out which then caused Al2O3 grains fractured. The finite element analysis indicated that the preferred whisker orientation had distinet influence on resistance of shearing stress in the wear interface in which the fine particle debris generated and microfracture occurred. Cutting tests show that higher tool life by wear was obtained when the plane parallel to the hot pressing direction was used as the rake face of the cutting tool.