| 摘要 |
PURPOSE:To obtain long-life tool parts by providing a thin plating of pure Ni on hard alloy and coating said plating with tungsten carbide so that the Co in the base material is prevented from getting eluted in the vicinity of the interface between coat and said base material. CONSTITUTION:When the 0.5-40mu-thick layer of the tungsten carbide containing more than 50 quantitative % of the tungsten monocarbide produced through the reaction that is made between tungsten halogenide and hydrogen carbide and between inactive gas and if required hydrogen gas at 800-1,200 deg.C on the surface of the hard alloy tool parts (e.g. drills, broaches and taps) made of steel or C0 of more than one of the carbides, nitrides and carbonitrides of the elements belonging to the groups 4a, 5a and 6a of the periodic table, 0,1-3mu-thick nickel layer is provided between said tool parts surface and said coat layer. Long life tool parts are obtained in whose base material the dilution of C0 is prevented due to the presence of said nickel. |
