Tungsten-molybd alloy electrode material for resistance welding

摘要

PROBLEM TO BE SOLVED: To provide a W-Mo alloy electrode material for resistance welding which allows life extension of electrodes even when welding is conducted with a large current.SOLUTION: A W-Mo alloy electrode material for resistance welding consists of a sintered body formed by blending pure W particle powder and pure Mo particle powder, preferably with a purity of 99.9% and an average particle size of 0.25-50 μm for the individual powders, so as to yield an Mo content of 37.5-87.5 mass% and sintering the resultant blend e.g. at a pressure of 1 GPa or higher and a temperature of 1,000°C or higher for 10 min. The relative density of the sintered body is 98.5% or higher, and the electrode material for resistance welding allows electrification of a large current, e.g. a 10,000A or higher welding current. The electrode material for resistance welding can be sintered by forming raw powders of a fine W particle and a Mo particle, e.g. of an average particle size of 4 μm or smaller, into a pressure powder molding, heat-treating the pressure powder molding in an atmosphere of a vacuum of 10Pa or lower or an atmosphere replaced with N gas, Ar gas, etc. at 450-1,200°C for 30 min or longer prior to sintering to purify the surface of the particle powders and sintering at relatively low pressure and temperatures.