Synthesis and Characterization of Laser-Ablated Cr-Alloy Coatings on 316L Stainless Steel

316 L stainless steel was surface modified with Cr-alloy thin film,synthesized by laser ablation of Cr-alloy paste layer.The influence of the power and scanning-speed of laser on the microstructures and tribological behavior of the Cr-alloy films was investigated with X-ray diffraction,scanning electron microscopy and mechanical probes.The results show that the scanning-speed/power of laser and paste-layer thickness had a major impact.For instance,as the laser power increased,the hardness and thickness increased of the Cr-alloy films,comprising columnar grains; as the scanning speed increased,the thickness decreased and the hardness changed in an increase-decrease manner.However,as the paste-layer thickness increased,the thickness of Cr-alloy film increased,accompanied by a decrease of the hardness.The optimized laser ablation conditions included: a laser power of 5.5 kW,a scanning speed of 8.5 mm/s and a Cr-alloy paste thickness of 0.15 mm.