碳化硅陶瓷的超声振动辅助磨削

采用普通磨削方式和超声振动辅助磨削方式对无压烧结SiC材料进行了磨削工艺实验,对不同磨削方式下磨削参数对磨削力比、表面损伤及亚表面损伤的影响进行了对比研究,并分析了超声振动磨削作用机制。实验结果显示,该实验中SiC材料去除主要以脆性去除为主,砂轮磨削力比随着磨削深度和进给速度的增加缓慢增加,随着主轴转速的增加略有减小;普通磨削时SiC工件亚表面损伤深度随着磨削深度、进给速度增加逐渐增加,而超声振动辅助磨削变化较小。与普通磨削相比,在相同的磨削参数下,超声振动辅助磨削的高频冲击使材料破碎断裂情况得到改善,且磨削力比减小近1/3,表面裂纹、SiC晶粒脱落、剥落等表面损伤较少,表面损伤层较浅,亚表面裂纹数量及深度都有较大程度降低,可以获得较为理想的表面质量。

Ultrasonic assisted grinding for silicon carbide

A grinding experiment was performed for silicon carbide (SiC) materials by Ultrasonic Assisted Grinding (UAG) and Normal Grinding (CG) methods. The effects of grinding parameters in different modes on the grinding force ratio, surface damage and sub-surface damage of the SiC materials were researched by using a dynamometer and a Scanning Electron Microscopy(SEM). Then the action mechanism of the UAG was researched. The experimental results show that brittle fracture is the main removal mode in grinding process. The grinding force ratio of the grinding wheel increases with the increases of cutting depth and feed rates slowly and decreases with the increase of pindle speed slightly. In the normal grinding, the sub-surface damage depth of a SiC workpiece increases with the increase of cutting depth and feed rates gradually, and that in the UAG has a smaller change. Under the same grinding parameters, the grinding force ratio in UAG process is reduced nearly 1/3 as compared with the results in CG process, and its surface damages, such as surface cracks, fall off of SiC grains, flaking of SiC are reduced and the thickness of surface damage layer is thinned. In addition, the density and depths of sub-surface cracks are reduced in a greater degree. It concludes that the UAG method can obtain ideal surface quality and high processing efficiency.