Pulver zum Gebrauch beim thermischen Spritzen

摘要

A powder for use in a thermal spraying coating process comprises particles consisting essentially of a metal carbide core coated at least partially with a layer consisting essentially of a nickel-chromium alloy containing the metal carbide dissolved therein. The particles are formed by heating a mixture of fine starting particles of the metal carbide in the presence of the nickel-chromium alloy under conditions effective to cause a portion, preferably 60 to 90 wt.%, of the starting metal carbide to dissolve in the Ni-Cr alloy. In an alternate embodiment suitable for higher temperature application, more than 90 wt. % of the starting carbide particles are dissolved. As the amount dissolved approaches 100 wt.%, the core essentially disappears. Coatings formed according to the invention show an unexpectedly large increase in both smoothness and erosion resistance.