Surface processing of metals using an oscillating laser beam Available to Purchase

The interest in surface processing with an oscillating laser beam is prompted by the need to process wider selected surface areas with a single melt pass. By mounting a flat mirror on a rapidly vibrating electromagnetic device, a high power CO₂ laser beam was made to oscillate over a moving sample surface. The resulting melt pool had a slight dog-bone shape, and, by controlling the current to the oscillating device, melt widths of 1.0-2.0 cm were attained. Since the objective of this work was to form hard, wear resistant surfaces on Inconel 625 alloy samples, the sample surfaces were treated with hardfacing alloys such as WC, TiC, SiC and Tribaloy. The WC and TiC particles were injected into the melt to form a metal matrix-carbide composite layer, SiC was laser consolidated as a thin fused layer, while Tribaloy was fed into the laser beam to form a cladding. Particle injection over the wider melted area was achieved through a slitted nozzle that formed a flat spray of the powder. Topographical and cross-sectional views of structures formed by the oscillating laser beam are described in this paper. Finally, the influence of the powder feed direction relative to the moving melt pool on factors such as the particle injection efficiency, the shape of the solidified melt pool and the nature of the overlap at the end of a circular pass is discussed.