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.

Abstract: A gas shroud comprises a chamber having a beam inlet, a gas inlet and an outlet portion. A shroud having an inner surface and an outer surface is operably associated with the outlet portion and is rotatable relative to the chamber. A drive system is operably connected to the shroud for rotating the shroud. A plurality of fins are positioned about the outer surface of the shroud and are rotatable therewith so that rotation of the shroud causes the environment surrounding the shroud to be expelled radially away therefrom.

Abstract: A beam monitor comprises a mirror for reflecting an incident beam of radiation to a target and for receiving a reflected beam from the target and has a surface on which the beams impinge. Incident and reflected beam channels are orthogonally disposed within the mirror. Each of the channels has an opening disposed in the surface for admitting the associated beam thereto. First and second detectors are operably associated with the mirror and each generates a signal indicative of a selected characteristic of the beam illuminating the associated channel. A controller compares the generated signals and thereby monitors at least one selected characteristic of the target or of the beam.

Abstract: A screw powder feeder has a rotary screw (12) disposed at the base of a hopper (10). The screw (12) comprises a twist drill bit. Powder is discharged into a chamber (18) and picked-up by a flow of gas. The pressure in chamber (18) is varied relative to the pressure in hopper (10) to control the feed rate for a given screw speed. Ultra-low feed rates are made possible by feeding gas into the hopper (10) through the screw (12) and controlling the relative gas pressures such that the pressure in the chamber (18) exceeds the pressure in hopper (10).

Abstract: A laser spray nozzle assembly includes a nozzle body with first and second spaced apart end portions. A beam passageway extends between the end portions and permits a laser beam to pass therethrough. A housing surrounds the second end portion. The housing is spaced from the second end portion and forms an annular passage. The housing has an opening coaxial with the beam passageway for permitting the laser beam to pass therethrough. A cladding powder supply system is operably associated with the passage for supplying cladding powder thereto so that the powder exits the opening coaxial with the beam.

Abstract: A predetermined characteristic of a laser beam is detected by disposing a reflector (11) in the path of the beam and coupling an electromechanical transducer (12) to the reflector to detect a mechanical response of the reflector to the incident beam.