Back to results
US 6,001,426 AGranted
High velocity pulsed wire-arc spray
AssigneeUtron Inc.
InventorsF. Douglas Witherspoon, Dennis W. Massey, Russell W. Kincaid
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeUtron Inc.
InventorsF. Douglas Witherspoon, Dennis W. Massey, Russell W. Kincaid
Estimating the term…
Wire arc spraying using repetitively pulsed, high temperature gas jets, usually referred to as plasma jets, and generated by capillary discharges, substantially increases the velocity of atomized and entrained molten droplets. The quality of coatings produced is improved by increasing the velocity with which coating particles impact the coated surface. The effectiveness of wire-arc spraying is improved by replacing the usual atomizing air stream with a rapidly pulsed high velocity plasma jet. Pulsed power provides higher coating particle velocities leading to improved coatings. 50 micron aluminum droplets with velocities of 1500 m/s are produced. Pulsed plasma jet spraying provides the means to coat the insides of pipes, tubes, and engine block cylinders with very high velocity droplet impact.
Apparatus for coating a substrate, comprising an electrically insulating capillary tube having an inlet and exit, a fluid supply connected to the inlet, electrodes in the capillary tube near the inlet and exit, an electrode power supply connected to the electrodes, wires forming a gap mounted outside the capillary tube near the exit, a gap power supply connected to the wires for creating an arc across the gap for heating and melting surfaces of the wires, a controller connected to the electrode power supply and to the gap power supply for igniting an arc across the electrodes and creating a plasma in the capillary tube and for igniting an arc across the gap for melting material on surfaces of the wires, wherein the plasma strips and atomizes the melted material into particles and accelerates the particles to the substrate.
A coating method, comprising feeding fluid into an inlet of a plasma generator tube, forming a gap with wires at an exit of the plasma generator tube, expanding the fluid within the plasma generator tube, forming pulsed arcs between electrodes in the plasma generator tube and in the gap between the wires, heating and energizing the fluid in the plasma generator tube into a plasma, directing the plasma through the exit and through the gap between the wires, melting material from the wires with the arc in the gap between the wires, impacting the melted material from the wires with the plasma and forming particles from the melted material from the wires, and accelerating the particles with the plasma toward a substrate and impacting the substrate with the particles and coating the substrate with the particles.
Coating apparatus comprising a plasma generator having an exit, a melt former near the exit, a power supply connected to the plasma generator for generating a plasma, and a power supply connected to the melt former for forming a melt near the exit, whereby plasma directed from the exit atomizes melted material into particles and accelerates the particles toward a substrate for coating the substrate.
Apparatus for performing a coating method, comprising means for feeding fluid into an inlet of a plasma generator tube, means for forming a gap with wires at an exit of the plasma generator tube, means for expanding the fluid within the plasma generator tube, means for forming pulsed arcs between electrodes in the plasma generator tube, and means for forming an arc in the gap between the wires, means for heating and energizing the fluid in the plasma generator tube into a plasma, means for directing the plasma through the exit and through the gap between the wires, means for melting material from the wires with the arc in the gap between the wires, means for impacting the melted material from the wires with the plasma and forming particles from the melted material from the wires, and means for accelerating the particles with the plasma toward a substrate and impacting the substrate with the particles and coating the substrate with the particles.
Dependencies are inferred from the claim text.