Research on Dilution of Laser Cladding Assisted by Pulsed Current Based on Orthogonal Experiment

Abstract

With characteristics of high cladding efficiency, small grain size and low porosity, follow-up feeding pulse current assisted laser cladding can realize online self-healing of cracks on the cladding layer and get a crack-free cladding layer. It is a very promising new laser cladding technology. In this study, effects of cladding parameters (laser power, scanning speed, powder feed rate, pulse current, pulse frequency and pulse width) on dilution rate of coating were discussed through a six-factor three-level orthogonal experimental design method. Results demonstrated that laser power, scanning speed and powder feed rate can influence dilution ratio greatly, while pulse current, pulse frequency and pulse width influence the dilution ratio slightly. Among the top three major factors, laser power can influence the dilution ratio mostly, followed by powder feed rate and scanning speed. The dilution ratio increases with the increase of laser power, scanning speed and pulse width, but it decreases with the increase of powder feed rate and pulse frequency. With the increase of pulse current, the dilution ratio decreases firstly and then increases.