An iron or copper based powder composition

摘要

An iron or copper based metal powder useful for plasma deposition of a coating that has a dry coefficient of friction .75 or less and readily conducts heat through the coating. The powder comprises (a) H2O atomised and annealed particles consisting essentially of (by weight) carbon .15-.85%, oxygen .1-.45%, an air hardening agent selected from manganese and nickel of .1-6.5%, and the remainder iron or copper, with at least 90% of the particles having oxygen and iron or copper combined in the lowest atomic oxygen form for an oxide of such metal. A method of making anti-friction iron powder that is economical, selectively produces FeO and promotes fine flowable particles. The method comprises (a) steam atomisation of a molten steel that excludes other oxygen, the steel containing carbon up to .4% by weight to produce a collection of comminuted particles, and (b) annealing the particles in an air atmosphere for a period of time of .25-2.0 hours in a temperature range of 427-760 DEG C (800 DEG -1400 DEG F) to reduce carbon in the particles to about .2% or sponge iron by reducing Fe3O4 or Fe2O3 in CO and (H2O steam) to attain nearly all iron with nearly all FeO and 0.1 to 0.85 C.