Laser welding of FeCoCrNiMnAl_x (x = 0, 0.75) high-entropy alloys fabricated by additive manufacturing

Abstract

In the present study, the laser melting deposition (LMD) technology was adopted to fabricate FeCoCrNiMn and FeCoCrNiMnAl0.75 high entropy alloys (HEAs). Then, laser welding method was used to join the HEAs in forms of similar (FeCoCrNiMnAl/FeCoCrNiMnAl and FeCoCrNiMnAl0.75/FeCoCrNiMnAl0.75) and dissimilar (FeCoCrNiMnAl0/FeCoCrNiMnAl0.75) combinations, respectively. Ultra-depth field microscope and electron backscatter diffraction detection were used to observe the macro-morphology and microstructure, respectively. It was found that the width of the weld bead and heat-affected zone with higher aluminium content was larger. In both base metals and welded joints, aluminium promoted the face-centered cubic (FCC) phase transfer into body-centered cubic (BCC), significantly refined the grain and the dislocation density of HEA is also increased, which increased strength and hardness, and decreased ductility. Highlights The FeCoCrNiMn/FeCoCrNiMn, FeCoCrNiMn/FeCoCrNiMnAl0.75, FeCoCrNiMnAl0.75/FeCoCrNiMnAl0.75 joints were produced by laser welding. The widths of the weld bead and heat-affected zone increased with higher Al content. The weld bead with higher content of Al exhibited higher strength and hardness, but lower ductility.

Alloying, phases and magnetic behaviour of mechanically alloyed FeNiMnCu-based high entropy alloys

“…There are several methods used to produce HEAs [29], such as mechanical alloying [30][31][32], arc melting [33,34], addtitive manufacturing [35,36], and laser cladding [37,38]. The phase structure and properties of FeNiMnCuCo and FeNiMnCuCr alloying systems produced by arc melting have been studied before [39,40].…”