Laser glazing/cladding as chrome plating alternatives

Abstract

Increasing environmental regulations and rising waste disposal costs are driving the need for economic chrome plating replacement technologies. This paper summarizes one of several chrome replacement research & development programs funded by the Air Force Pollution Prevention office. This work focuses on two laser-based coating processes – laser cladding and laser glazing – for the application of a thick (5-25 mils) uniform coating with similar if not superior mechanical performance to that of hard (wet) chrome plating. All experiments were performed using a flattop continuous wave carbon dioxide laser, operating at 10.6 micron.This paper describes the laser cladding and glazing techniques, the processing parameters developed and the mechanical performance of the resultant coatings. Emphasis will be placed on the laser glazing technique developed under this effort. The technique uses the laser’s rapid surface heating effect to melt, re-flow and consolidate protective coatings deposited using any type of thermal spray technique – in this case, a flame-spray coating system. Post flame-spray treatment using laser glazing transformed an economical but porous coating into a uniform, pore-free coating with superior performance characteristics to that of chrome. Materials characterization and mechanical property test results are discussed.Increasing environmental regulations and rising waste disposal costs are driving the need for economic chrome plating replacement technologies. This paper summarizes one of several chrome replacement research & development programs funded by the Air Force Pollution Prevention office. This work focuses on two laser-based coating processes – laser cladding and laser glazing – for the application of a thick (5-25 mils) uniform coating with similar if not superior mechanical performance to that of hard (wet) chrome plating. All experiments were performed using a flattop continuous wave carbon dioxide laser, operating at 10.6 micron.This paper describes the laser cladding and glazing techniques, the processing parameters developed and the mechanical performance of the resultant coatings. Emphasis will be placed on the laser glazing technique developed under this effort. The technique uses the laser’s rapid surface heating effect to melt, re-flow and consolidate protective coatings deposited using any type of t...