电火花机械复合磨削反应烧结SiC陶瓷的表面特征

发布时间：2018-06-16 13:46

本文选题：反应烧结SiC + 电火花机械复合磨削　；参考：《光学精密工程》2016年09期

【摘要】：研究了基于电火花机械复合磨削技术加工的反应烧结碳化硅(RB-SiC)陶瓷的表面特征。用电火花机械复合磨削(EDDG)、电火花磨削(EDG)以及普通磨削(CG)三种方法加工RB-SiC陶瓷,并采用激光共聚焦显微镜和扫描电子显微镜对加工后的SiC陶瓷的表面粗糙度、表面形貌及微观裂纹进行测量和对比试验,获得了RB-SiC陶瓷的EDDG加工特性。实验显示:EDDG加工的RB-SiC陶瓷的表面粗糙度优于EDG加工的表面粗糙度,为0.214 9μm,但比CG加工的表面粗糙度0.195 6μm略差。对加工后的SiC陶瓷表面形貌观察显示,传统磨削加工后的表面存在明显划痕,EDG加工表面主要由放电凹坑组成,而EDDG加工表面同时存在放电凹坑和磨削划痕;另外,传统磨削表面也存在磨削裂纹和晶界裂纹,但EDG加工后的表面只存在热裂纹,而EDDG加工后的表面存在磨削裂纹和热裂纹,不过热裂纹可以用金刚石磨粒磨削去除。对比实验显示RB-SiC陶瓷的EDDG加工与EDG和CG加工获得了不同的表面特征。
[Abstract]:The surface characteristics of reaction-sintered silicon carbide (RB-SiC) ceramics based on EDM were studied. RB-SiC ceramics were machined by EDM mechanical composite grinding (EDM), EDM grinding (EDG) and common grinding (CGG). The surface roughness of sic ceramics was obtained by laser confocal microscope and scanning electron microscope. The EDDG machining properties of RB-SiC ceramics were obtained by measuring and comparing the surface morphology and microcracks. The experimental results show that the surface roughness of the RB-SiC ceramics fabricated by WEDDG is better than that of EDG by 0.214 9 渭 m, but it is slightly worse than that of CG (0.195 6 渭 m). The observation of the surface morphology of sic ceramics after machining shows that there are obvious scratches on the surface after traditional grinding. The EDG surface is mainly composed of discharge pits, while the EDDG machined surface has discharge pits and grinding scratches. There are also grinding cracks and grain boundary cracks in the traditional grinding surface, but only hot cracks exist on the surface of EDG after machining, while there are grinding cracks and hot cracks on the surface of EDDG after machining. The non-superheated cracks can be removed by diamond abrasive grinding. The experimental results show that the EDDG machining and EDG and CG machining of RB-SiC ceramics have different surface characteristics.
【作者单位】：哈尔滨工业大学机电工程学院;哈尔滨理工大学机电学院;
【基金】：国家973重点基础研究发展计划资助项目(No.2011CB013202)
【分类号】：TG580.6

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