| 摘要 |
PURPOSE:To reduce porosity in a coating layer and to improve its wear resistance by holding the temp. of the surface of a base metal to a specified one and plasma-spraying WC alloy powder mixed with Co, Cr, Ni or the like on the surface of the base metal under the reduced pressure. CONSTITUTION:The surface of a thermal spraying base metal is thermal-sprayed with alloy powder contg., by weight, 25 to 35% Co, 6 to 12% Cr, 5 to 10% Ni, 1.5 to 9% Si+B+C and the balance WC under the reduced pressure in the state where in the temp. of the surface of the above material is held to >=300 deg.C. By this thermal spraying, a spray coating layer having <=3% porosity is formed. Because the thermal spraying is executed under the reduced pressure, differently from thermal spraying in the air, the contamination of air does not occur and its porosity can be reduced. In this way, the formation of an excellent wear resistant coating layer is permitted, and the components to be added newly are general Ni, Cr, Si, B, C or the like which are inexpensive, so that the service life of a wear resistant member can remarkably be prolonged without raising the cost of the spray powder. |
