PROCESS FOR OBTAINING TIGHT COMPONENTS BY POWDER METALLURGY

摘要

The process comprises: mixing a metallic powder defined by iron or nickel or copper or mixtures of two or three elements thereof and provided that the sum thereof defines at least 55% in mass of the metal matrix of the component to be produced, and a molybdenum disulfide powder as a densification agent and as a solid lubricant with a content from 3 to 30% in volume; filling a mold with the mixture and obtaining a compact presenting from 5 to 25% in volume of primary pores (P1); and subjecting the compact to a temperature and for a time sufficient to allow the reaction of the molybdenum disulfide with the matrix, forming iron sulfide, nickel sulfide or copper sulfide, and the diffusion of the molybdenum in the matrix; and subjecting the compact to a temperature sufficient to transform the sulfide into a liquid phase, filling the primary pores (P1) before finishing the sintering step of the compact.