Super-Smooth Grinding Behavior of SiC Ceramics by the Use of Coarse Diamond Grinding Wheel

Abstract

A new super-smooth grinding method for SiC ceramics was proposed by the use of coarse diamond grinding wheel. It can enhance ultra-precision grinding efficiency in comparison with ELID (electrolytic in-process dressing) mirror grinding with super-fine diamond grinding wheel. In grinding, wheel moving direction is vertical to cutting direction different from traditional plunge and traverse grinding and dressing + iron-truing was also employed to protrude and truncate grit cutting edges, improving grit protrusion feature. First, formation of super-smooth ground surface was theoretically analyzed on the base of grit cutting depth and surface roughness. Next, theoretical effect of grinding parameters and grit protrusion parameters on grit cutting depth and surface roughness was discussed. Then, orthogonal experiments were conducted to investigate effect of grinding parameters on surface roughness. Finally, dressing experiment and iron-truing experiment were carried out respectively to investigate ductile-mode mirror grinding behavior in connection with wheel moving speed and grit protrusion feature. Theoretical analysis showed that grit cutting depth and surface roughness depend on wheel rotating speed, wheel moving speed, grit cutting edge number and grit cutting edge angle, but they were not dominated by the depth of cut. Experimental results showed that a super-smooth ground surface can be obtained by decreasing wheel moving speed and improving grit protrusion feature. In addition, the ductile mode grinding may be conducted to realize mirror grinding of SiC ceramics by using wheel moving speed of 5 mm/min and dressing + iron-truing conditions before grinding.