Laser-deposited CoCrMo alloy: Microstructure, wear, and electrochemical properties

CoCrMo alloy was deposited on a metallic substrate using laser engineered net shaping (LENS™) – a laser-based additive manufacturing technique. Several samples with five layers of deposit were fabricated at different combinations of laser power, powder feed rate, and scan velocity to study their influence using L4 Orthogonal array. The deposits were evaluated for their microstructure, hardness, wear resistance, and electrochemical performance. Grey relational grade analysis and analysis of variance were applied to identify optimum process parameters. The x-ray diffraction and microstructural analysis of the deposits showed uniform and fine microstructural features. Our experimental results revealed that the coatings fabricated using high laser power (350 W), low powder feed rate (5 g/min), and high scan velocity (20 mm/s) provide the highest hardness (446 ± 2.87 Hv) and wear resistance (1.80 ± 0.0007 mm3/Nm). However, the corrosion resistance was observed to be high for the deposits fabricated using low laser power (200 W), low powder feed rate (5 g/min), and low scan velocity (10 mm/s).