Additive manufacturing of interstitial-strengthened high entropy alloy: Scanning strategy dependent anisotropic mechanical properties

A non-equiatomic interstitial-strengthened high entropy alloy (iHEA), Fe49.5Mn30Co10Cr10C0.5 (at.%), is manufactured by laser powder-bed fusion (LPBF) with stripe and chessboard scanning strategies. The present study highlights the correlation between the laser scanning strategies with resulting microstructure, textures, and anisotropic mechanical properties in as-built iHEA. The results show that the LPBF processed iHEA exhibits an excellent strength-ductility synergy due to the combined deformation mechanisms of dislocation slip, martensite phase transformation- and nano twinning-induced plasticity. The samples printed by the stripe scanning strategy show more evident mechanical anisotropy than that of the chessboard-scanned samples. The difference in the degree of mechanical anisotropy is mainly attributed to the heterogeneous grain morphology and crystallographic texture resulted from different scanning strategies.

Automated summary

A non-equiatomic interstitial-strengthened high entropy alloy (iHEA), Fe49.5Mn30Co10Cr10C0.5 (at.%), is manufactured by laser powder-bed fusion (LPBF) with stripe and chessboard scanning strategies. The relationship between laser scanning strategies and resulting microstructure, textures, and anisotropic mechanical properties in as-built iHEA is investigated. Results show that LPBF processed iHEA exhibits excellent strength-ductility synergy due to combined deformation mechanisms. The mechanical anisotropy is more evident in samples printed by the stripe scanning strategy compared to the chessboard-scanned samples, attributed to heterogeneous grain morphology and crystallographic texture resulting from different scanning strategies.