Abstract: A nozzle for delivering particulate matter into a molten pool created on a substrate includes a core through which the particulate is delivered, an annulus surrounding the core for simultaneously delivering a shield gas toward the molten pool and shield gas conditioning apparatus. The conditioning apparatus includes a system of wire mesh screens and a cup for directing the gas flow.

Abstract: A method of applying abrasive materials to a substrate includes the steps of forming a relatively small pool of superheated molten metal at the surface of the metal substrate by creating an interaction area on the substrate with a localized high energy source. A powder system is injected into the pool. The powder system comprises metal matrix powder and abrasive powder. The abrasive powder includes abrasive particles having an encapsulating thermal insulating layer for preventing the abrasive particles from being melted by the molten metal in the pool. The substrate is then moved relative to the energy source, thereby allowing the pool to resolidify.

Abstract: A process for preventing crack formation in nickel alloy substrates having a gamma-prime phase includes providing a substrate comprised of a nickel alloy having a gamma-prime phase. A portion of the substrate is irradiated with a laser beam and thereby forms a molten pool of the alloy. A supply of coating particles are dispersed within the pool, the particles are comprised of a nickel alloy having gamma-prime forming constitutents. Rapid relative motion between the beam and the pool is effected so that the pool rapidly solidifies and thereby minimizes the formation of gamma-prime therein and adjacent thereto.