| 摘要 |
PROBLEM TO BE SOLVED: To prevent wear of a tip body by removing a bonded metal part between intermetallic compound particles exposed on a surface, and forming a recess at the removed part of the surface. SOLUTION: Hard intermetallic compound particles 17 such as WC or the like are sintered under predetermined sintering conditions, and formed substantially in a spherical shape. This sphere is rolled together with diamond powder between two grinding stones held at a predetermined interval, polished up, and hence its surface 19 is mirror finished. Then, for example, spheres are rubbed together by a barrel, and small pieces of the particles 17 existing between the particles 17 of the surface 19 are removed. Simultaneously, soft bonding metal 18 part of Co or the like is worn and removed, and a recess 2 of an irregular pattern is formed on the removed part. The rubbing together is further continued to remove edge parts of a periphery of the recess 2 of the particles 17 exposed on the surface 19 is removed by colliding the spheres each other, a rounded corner 3 is formed to the ball 1. |
