METHOD OF MANUFACTURE OF HARD-ALLOY ARTICLES AT VARYING MICRO-HARDNESS OF SURFACE LAYERS Russian patent published in 2003 - IPC

FIELD: mechanical engineering and metallurgy of hard alloys; manufacture of sintered-carbide cutting tools at gradient of properties in cross section of article. SUBSTANCE: proposed method includes application of titanium layer, 1-3 mcm thick on hard-alloy base by cathode-ion bombardment; hard-alloy base is sintered preliminarily at temperature of 1050-1250 C; then, heat treatment is performed at temperature of final sintering of article. At temperature control, extremum of micro-hardness is obtained at definite depth of surface layer and at thickness control, definite difference between micro-hardness of surface and main layers of material is obtained. EFFECT: possibility of controlling gradient of properties of surface layers of hard-alloy articles. 3 cl, 5 dwg