Disaggregated Metal and Carbide Catchment Efficiencies in Laser Cladding of Nickel-Tungsten Carbide Using a CO2 laser, the effects of power, powder feed rate, and travel speed were studied to determine their influence on the efficiency of depositing a nickel tungsten carbide clad coating

Composite coatings made of nickel matrix reinforced with tungsten carbide particles are one of the dominant wear-protection systems in mining, oil, and gas applications. In these applications, the balance of powders forming the final coatings is crucial to the final product. This paper presents for the first time an analysis of powder utilization efficiency ("catchment efficiency") where the metallic powders (mostly nickel) and tungsten carbide are discriminated. Experiments were performed using a CO2 laser system with coaxial powder deposition, and the effects of power, powder feed rate, and travel speed were tested. The metal efficiency was higher than the carbide in all tests. Increasing laser power resulted in increased efficiency for both metal and carbide. Increasing powder feed rate decreased nickel efficiency and increased carbide efficiency, with the overall powder efficiency being approximately constant. Increasing travel speed resulted in strong reduction of efficiency for both carbide and nickel.