| 摘要 |
PURPOSE:To produce a superhard alloy member of superior heat resistance and high speed machinability by sintering a hard phase having B1 type crystalline structure and a WC phase with a ferrous metal as a binding phase, using this as a base material and coating hard compds. of specific metals as well as Al2O3, AlN, ert. on the surface thereof. CONSTITUTION:In the stage of producing a superhard alloy as a cutting tool or an abrasion resistant tool, the hard phase consisting of carbide, nitride and oxide having BI type crystalline structure such as Ti, Ta, Na, Nb or W expressed by the formula[I]and a WC hard phase are sintered with a ferrous metal such as Co as a binder, whereby a superhard alloy member is produced. In the sintering, the partial pressure of CO in the sintering atmosphere is kept at >=5 Torr when temp. is >=600 deg.C and a <=10 Toor vacuum atmosphere is created when the temp. is above the liquid phase aperaing temp. The surface of such superhard alloy member is further coated with one or >=2 kinds of carbide, nitride, oxide and boride of IVa, Va, VIa group elements of periodic table, Al2O3, AlN at 1-20mu thicknesses, whereby the machinability is improved. |
