为揭示磨削加工中砂轮单个磨粒对工程陶瓷划擦力的作用规律,利用单颗粒金刚石磨具划擦实验来模拟砂粒实际磨削过程。分析单颗粒金刚石的划擦力产生机理,认为划擦力是由磨粒对试件的挤压力和摩擦力构成。采用不同磨削刃顶锥角与尖端圆弧半径的自制金刚石颗粒,改变划擦深度与试件进给速度,探讨金刚石颗粒磨削刃特征、划擦实验参数对Si3N4陶瓷试件划擦法向力与切向力的影响。结果发现,试件法向划擦力随磨削刃特征参数和划擦用量增大而增加;切向划擦力随磨削刃尖端圆弧半径逐渐递减,与顶锥角和划擦用量保持递增关系。
To reveal the inherent laws between single abrasive particle of diamond wheel and fracture strength of engineering ce- ramics during the grinding, a special single diamond tool was introduced to substitute the actual wheel. The mechanism of scratc- hing force for single diamond was investigated, considering that the scratching force was consist of extrusion pressure and friction between workpiece and abrasive grain. And then, the relationships between cutting edge features, scratching parameters and scratching force of silicon nitride were analyzed with diverse angle of tip cone, radius of curvature, scratching depth, and feeding rate of workpiece. The results show that the normal scratching force improves with the raise of cutting edge parameters and scratc- hing parameters. However,the tangential scratching force keeps a decreasing relation with angle of tip cone of cutting edge, and increases with the increment of scratching parameters.