SURFACE COATED SINTERED HARD ALLOY AND ITS PRODUCTION AND SURFACE COATED STEEL PRODUCTS AND ITS PRODUCTION

摘要

PURPOSE:To produce the sintered hard alloy coated with a wear resistant film by specifying the supply current to an evaporating source, the bias voltage to the sintered hard alloy, film forming temp. and reactive gaseous pressure in an ion plating method of a vacuum arc discharge type. CONSTITUTION:A substrate 14 (sintered hard alloy) is mounted on a turn table 12 in a reaction vessel 10 and the evaporating source 16 (Ti) is provided on the surround side wall of the reaction vessel 10. The pressure in the reaction vessel 10 is evacuated through a port 20 to about =1X10-5Torr. Gaseous nitrogen is then introduced from a supplying port 18 to attain 10X10-3Torr pressure and =80A current is supplied to the evaporating source 16 to impress -200 to -800V bias voltage to the substrate 14. The film forming temp. is maintained at =450 deg.C and the turn table 12 is rotated to form the film (about 0.2 to 20mu film thickness) on the substrate 14. The surface coated sintered hard alloy coated with the nitride of Ti having the B1 structure which has the color entering 0.47=x=0.49, 0.34=y=0.36 in the XYZ color specification method stipulated in JIS Z 8701 is obtd. in this way.