鋳鉄ボンドダイヤモンド砥石の製作

抄録

A diamond grinding stone bonded by sintered cast iron powder as the matrix has been developed. This stone was applied to lapping, superfinishing, honing and grinding, and showed a highly improved grinding ability especially for hard and brittle work materials. This paper describes the manufacturing process of the stone and some results of the experiments concerning the stone materials. Diamond abrasives are mixed with cast iron powder and carbonyl iron powder which is added in order to get strong abrasive retention. This mixture is compacted into a grinding stone by press forming or roll forming process and then sintered 1 140°C for 30 minutes in an ammonia cracking gas atmosphere. As the result, the diamond particles are distributed uniformly and bonded firmly in the cast iron matrix which consists of pearlite, ferrite and flake graphite, so that the grinding property of the stone is improved and the dressing becomes relatively easier. The effects of the size and the content of the abrasive and the amount of the carbonyl iron powder are discussed from the mechanical properties of the grinding stone estimated by radial crushing strength test and bending test. It has been found that the residual quantity of the diamond at the sintered temperature is about 84 wt%.