Experimental study on microstructure of high-entropy alloy reinforced with ceramic particles formed by laser cladding

The microstructure of SiC ceramic particle-reinforced FeCoNiCrAl high-entropy alloy specimens prepared by laser cladding was observed, and the effects of SiC and Al content and laser process parameters on the microstructure of laser cladding high-entropy alloy were analyzed. The results show that increasing the scanning speed and laser power or reducing the powder feeding rate is conducive to obtaining smaller grains and forming a denser microstructure. However, when the laser power and scanning speed are too large, pores and unmelted powder will appear. Increasing the content of SiC ceramic particles significantly increases the number of heterogeneous nucleation points, resulting in a decrease in the grain size in the cladding layer and a more tortuous grain boundary, which is conducive to improving comprehensive performance. However, when the SiC content is too high, defects, such as cracks and inclusions, are prone to occur. With the increase of Al content, the grain size in the cladding layer increases first and then decreases.