High entropy alloys with strength-ductility synergy and excellent energy absorption property fabricated by SLM

In this study, the effects of different processing conditions on the microstructure and mechanical properties of SLM-fabricated AlCoCrFeNi 2.1 high entropy alloy were systematically investigated through physical and mechanical property measurements, microstructural characterization, and semi-quantitative analysis of the yield-strength contributions. The results show that, with increasing laser energy density, the alloy gradually evolves from an FCC + BCC dual-phase microstructure to an FCC-dominated dual-phase structure. The yield strength generally decreases, whereas the compressive ductility progressively improves; meanwhile, both the peak compressive strength and volume energy absorption exhibit non-monotonic variations. The semi-quantitative decomposition of strengthening contributions indicates that solid-solution strengthening is relatively insensitive to processing variations, whereas grain-structure evolution and changes in the dislocation substructure exert a more pronounced influence on the yield strength. These findings provide microstructural and mechanistic insights into achieving a favorable strength-ductility synergy and superior energy-absorption capability (178.4 MJ m −3 ), in SLM-fabricated high entropy alloys.