| 摘要 |
PURPOSE:To prevent the occurrence of cracks in the surface of a sintered alloy in the sintering of Ti-base cermet by keeping a partial pressure of CO in a temp. raising stage to a sintering temp. to be held under a specified partial pressure of CO. CONSTITUTION:Powder consisting of 70-97wt% hard compound phase composed of Ti as a principal component, a IVa, Va or VIa group metal and >=1 kind of nonmetallic component selected from carbon, nitrogen and oxygen, and 3-30% binding phase of >=1 kind of iron group metal is mixed and die-pressed. The die-pressed body is heated from ordinary temp. to 1,000 deg.C in a vacuum, and a part or the whole of a temp. raising stage before attaining the sintering temp. is kept under 0.1-1 Torr partial pressure of CO. The die-pressed body is then held in a vacuum and sintered at the prescribed temp. By this method a sintered hard alloy (cermet) free from surface cracks for a tool, etc. is obtd. |
