Experimental study on microstructure and tensile properties of high entropy alloy by laser melting deposition

The high-entropy alloy(HEA) samples FeCoNiCrTi0.3, FeCoNiCrTi0.5, FeCoNiCrAl0.5 were designed and prepared by laser melting deposition (LMD), and their microstructure characterization were observed, physical phase analysis, and tensile properties were investigated. The results show that the microstructure at the top of the same LMD-HEA sample is smaller than that at the bottom. FeCoNiCrTi0.5, FeCoNiCrTi0.3, and FeCoNiCrAl0.5 are all single-phase FCC structures, and the results of XRD and EBSD analysis are consistent. The fracture stroke of FeCoNiCrTi0.3 is greater than that of FeCoNiCrTi0.5, the tensile strength of FeCoNiCrTi0.5 is larger but the section shrinkage is smaller. The maximum breaking load of FeCoNiCrTi0.5 is slightly larger than that of FeCoNiCrAl0.5, the tensile strength of FeCoNiCrTi0.5 is larger than that of FeCoNiCrAl0.5, the fracture shrinkage is smaller than that of FeCoNiCrAl0.5, and there is little difference in the elongation. The number of dimples in the tensile fracture of FeCoNiCrTi0.3 is significantly higher than that of FeCoNiCrTi0.5, and the fracture of FeCoNiCrTi0.5 is more flat and smooth. This study guides the study of the mechanical properties of LMD-HEA and is helpful for the high-performance design and integrated manufacturing of LMD-HEA composite components.