JPS6453790A - Laser beam build-up method - Google Patents

Abstract

PURPOSE:To obtain a build-up layer excellent in wear resistance and surface property by supplying mixed powder of build-up alloy powder with wear resistant particle powder onto base material and projecting a laser beam having conditions to melt both powders to precipitate wear resistant particles in the process of cooling and solidifying. CONSTITUTION:A silicide, a boride, etc., besides a carbide are used as the wear resistant particles. On the other hand, it is preferable to select properly from a characteristic required for the build-up layer and the relation with the base material as a build-up alloy and a Ni-Cr alloy, etc., with respect to the iron base material, for instance, are used for this purpose. While or after the above-mentioned mixed powder is supplied to a build-up part of the base material, the laser beam is projected to melt the mixed powder. The conditions to melt not only the build-up alloy powder but also the wear resistant particle powder such as the carbide are required as the irradiation conditions of the laser beam. Continuously, a molten pool is rapidly cooled and solidified to form the build-up layer by stopping the laser beam irradiation or moving the laser beam irradiation position. At this time, the heat resistant particles such as the carbide which are once molten in the build-up alloy are dispersed and crystallized.