Effect of electromagnetic field on microstructure and hardness of laser cladding Fe-based amorphous crystalline coating

Based on the laser cladding technology, in order to further improve the amorphous rate and coating performance, the improvement of the hardness of the coating by the electromagnetic field was investigated on the basis of the coating prepared by the best laser parameters. In the process of coating preparation, different strength electric field, magnetic field and electromagnetic field are assisted. The influence of auxiliary field strength on the microstructure and amorphous rate of the cladding layer is analyzed by SEM. The hardness of the coating is tested by Vickers hardness tester. The influence of auxiliary field strength on the microhardness of the coating is analyzed. The best electromagnetic parameters required for coating preparation are obtained by the analysis results. The results show that when the laser process parameters remain unchanged, when the current intensity is 10 A and the magnetic field intensity is 10 mT, the average microhardness of the coating is the largest, reaching 902.3HV0.5, which is 68.2HV0.5 higher than that of the coating without electromagnetic assistance, and the improvement rate is 8.2 %. At the same time, the mechanism of coating hardness improvement was revealed by analyzing the phase and element distribution of the coating corresponding to the optimal electromagnetic field parameters.