Interlayer Dilution Zone Elemental Profiling and Microhardness Measurements for Individual Laser Clads

A detailed study of microstructure and microhardness distribution at clad-to-substrate interlayer dilution zone as well as elemental profiling were carried out for individual laser clads. Tungsten carbide (44 712-10) and nickel alloy (1560) powders were used for individual clad synthesis at the surface of low alloy steel by coaxial laser cladding technique. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) revealed partial tungsten carbide (WC) melting and secondary chromium carbides formation near WC grains. Iron and nickel elemental profiles were quantified by EDX technique to estimate interlayer dilution zone dimensions. Interlayer zone depth in the clad center increased from 15 to 80 µm when laser power was changed from 0.8 to 1.5 kW while at the outer clad regions it varied in 3–20 µm range. Interlayer clad-to-substrate zone microhardness study revealed a non-uniform dependence of hardness distribution for single clads synthesized with varying laser power.