SURFACE COVERED SINTERED HARD ALLOY MEMBER

摘要

PURPOSE:To enhance the cutting characteristics of the titled member by forming a solid soln. coat layer of an Hf compound and a Ti compound on the surface of a sintered hard alloy substrate and forming a layer of titanium nitride or titanium carbonitride on the coat layer. CONSTITUTION:Iodine 1 is kept at a predetermined temp. with each thermostat 2 to generate iodine vapor, and the vapor is reacted with Hf 3 and Ti 4 heated to a predetermined temp. in heating furnace 5. HfI4 gas and TiI4 gas thus generated are reacted with a reactive gas such as hydrocarbon gas or N2 by glow discharge on each sintered hard alloy substrate 7 in substrate heating high frequency induction heating furnace 6 under reduced pressure to form a solid soln. coat layer of (Hf.Ti) C or (Hf.Ti)N. The introduction of iodine vapor into Hf metal 3 is then stopped, and N2 gas or N2 gas and hydrocarbon gas are introduced as reactive gases to form a layer of titanium nitride or titanium carbonitride.