1982 Volume 90 Issue 1044 Pages 427-432
Recently, various types of ceramic hard materials are being used for machine parts. The superhard abrasive grains; diamond and CBN-boron nitride, are indispensable tool material for the cutting and grinding of these hard materials. The major problem in these tools is wear, and hence, much attention are being paid to the wear research of superhard abrasive grains and wheels. In this study, a series of pin-on-disc grain wear test has been performed for six different hard abrasive grain types, including diamond and CBN, against various hard materials such as sintered carbide, sintered alumina and sintered magnesia. The wear test was made at the speeds of 300 to 1200m/min under the vertical loads of 2.5N or 4.5N. Thus, the relative wear ranking of grain was determined for each disc material. This result was discussed based on the results obtained on SEM-micrograph of worn surface of grain, frictional force measurement, disc wear volume measurement and wear debris observation. From the wear research it is evident that the relative wear ranking is independent of the disc material used. Namely, the most small wear was obtained on the diamond grain as expected, followed by the CBN grain, and the silicon carbide grain types show the largest wear, and the alumina grain types lie between the superhard grain types and the silicon carbide grain types. Increased sliding speed seems to increase wear rate. Many thermal cracks were observed on the wear surface of the grain, especially when the sintered alumina or the sintered SiC disc is used. The crack will increase the grain wear at high sliding speeds.
