The Effect of Porosity of CBN Grinding Tools on Grinding Properties

Abstract

The CBN grinding wheels with different porosity, which used 100/120 CBN grind grain and 15μm glass powder as main starting materials, pore creating material as auxiliary material, were prepared by conventional sintering technology; Used GCr15 bearing steel which quenching hardness was 60HRC as ground materials, investigated the effect of porosity of CBN wheel on its cutting ability. In this paper , the metal removal rate was measured by electronic analytical balance, surface roughness of GCr15 was analyzed used LEXT laser scanning confocal microscope and the surface topography of grinding face was observed used scanning electron microscope. The investigated results showed that the metal removal rate acutely increasing with the porosity of wheels increasing in same loading weight, it reached 0.445g/min with 41% porosity in 3500g loading weight, at the same time, the difference of surface roughness caused by variation of porosity of CBN grinding wheel was slight, it did not severely lower machining precision of workpiece.