Analytical and Experimental Study of Laser Cladding of Ni/WC Metal Matrix Powders Reinforced with Rare Earth Elements Using a High Power Direct Diode Laser

The corrosion and wear are major limiting factors for steel in the harsh environments and can be controlled by depositing protective passive coatings. Nickel based alloy cladding of steel offers a solution by enabling better corrosion and wear resistance, and high bonding strength. The laser surface cladding of steel was conducted using a high power direct diode laser. Layers of tungsten carbide in Ni (40%Ni-60%WC) combined with 1% and 2% Lanthanum Oxide (La2O3) and Cerium Oxide (CeO2) were deposited on ASTM A36 steel substrate. The X-ray diffraction and scanning electron microscopy were employed to study the morphology, microstructure, and phase evaluation of the cladded layer. Further, anodic polarization on the laser cladded coupons in 3.5 wt. % NaCl shows significant enhancement of the corrosion resistance. The hardness to modulus of elasticity ratio (H/E) was used to analyze the wear. It was found that the addition of 1% La2O3 or 1% CeO2 to Nickel-based alloy (40% Ni-60% WC) improves the corrosion resistance and microhardness significantly but the wear resistance marginally