Experimental Research On Grinding Si₃N₄ With Chromium Corundum Wheel

With the continuous development of technologies of ultra-precision machining and engineering ceramics, the efficient and low cost ultra-precision grinding for engineering ceramics has come true with plain grinding wheel on plain grinding machine. In this research, ultra-precision grinding experiment for Si3N4 with chromium corundum grinding wheel is studied, and by analyzing on variations of the surface roughness of workpiece, the surface topography of grinding wheel and workpiece, the mechanism and modeling of this machining are established.Being poor of their mechanical properties, plain grinding wheel will generate lots of micro blades composed of fractured abrasive grains during machining and truing, chromium corundum wheel can carry out ductile-regime grinding Si3N4 with cutting of these micro blades and the abrasive grains will be worn down finally. The surface quality of workpiece can be enhanced effectively during this ductile-regime grinding.By lots of experiment, we find that friction and squeezing action brought by blunt abrasive grains will reduce the surface quality of work piece; therefore when grinding ceramics the plain grinding wheel should be trued in time in order to keep tartness of abrasive grains. When Si3N4 is ground by chromium corundum wheel, mirror finish of workpiece surface can be come true after twice or thrice truing of grinding wheel.By analyzing on variations of the grinding force, the surface roughness of workpiece, the surface topography of grinding wheel and workpiece, the reasons of the depth of grinding and the grain size, as important influencing factors of ultra-precision grinding ceramics by plain grinding wheel, influencing ultra-precision grinding are studied.The conclusions and results in this paper are of importance to the researches and practices of ultra-precision grinding. Moreover, the built model of plain grinding wheel ultra-precision grinding engineer ceramics can be supported effectively by test data of the grinding force, the surface roughness of workpiece, the surface topography of grinding wheel and workpiece in our research.