| 摘要 |
PURPOSE:To obtain the coated and sintered alloy part which is excellent in toughness and wear resistance at low cost by coating the surface of Mo-based hard alloy base material whose surface is enriched with specific W and Mo carbo-nitrides over its 3-200 micron-thick surface layer with a composition consisting of a specific transition metal, B, and C. CONSTITUTION:The surface of the sintered alloy base material, obtained by combining double W and Mo carbides and, as needed, one or more carbides of the transition metals of the IVa, Va and VIa groups in the periodic table as hardening substance with a transition metal element selected from Cr, Mo and W, is enriched with a lower carbide or carbonitride of the formula (MoXW1-X)2C or (MoXW1-X)2(CN) over its 3-200 micron thick surface layer and then coated with one or more of compounds containing the said transition metals and one or more of B, C and N and/or Al2O3 at 500-1,500 deg.C and 1-1,000Torr for 10-1,000min in an atmosphere of CO to partially replace the expensive W with Mo, whereby obtaining the coated sintered alloy parts excellent in toughness and wear resistance. |
