| 摘要 |
PURPOSE:To harden the inside surface of the micropore provided in a base material, by inserting a wire rod made of a material for surface hardening into said micropore, and coating the inside surface of the micropore by a wire explosive spraying method, then subjecting the surface to a heat-treatment. CONSTITUTION:A micropore 1' is formed to the work 1 which is a nozzle or the like by an ordinary machining method, whereafter a fine wire 2 consisting of a material for surface hardening such as Mo, W, Ti, Cr, V or the like is installed in the hole 1' without direct contact with said hole. After the inside of the pore 1' is evacuated, large electric current is supplied instantaneously to the wire 2 by a wire explosive spraying device 3 consisting of a capacitor (a), a resistor (b), a power source (c), a swith (d), etc. to heat and evaporate the wire. The material of the wire 2 is vacuum deposited and coated on the inside surface of the pore 1' by this treatment. The thickness of the coating is easily controlled with the diameter of the wire 2, and the above-described current value to be supplied is determined by the electric resistance value of the constituting material for the wire 2, and the vapor pressure characteristic value in the stage of evaporation by heating. After the treatment, the work is heat treated in a vacuum heat treatment furnace to diffuse the carbon from the base material in the coating and to form carbide, whereby the inside surface of the pore is hardened. |
