In-situ hot forging directed energy deposition-arc of CuAl8 alloy

Abstract

CuAl8 alloy finds applications in industrial components, where a good anti-corrosion and anti-wearing properties are required. The alloy has a medium strength and a good toughness with an elongation to fracture at room temperature of about 40%. Additionally, it has a good electrical conductivity, though lower than that of pure Al or pure Cu. Despite these characteristics, additive manufacturing of the CuAl8 alloy was not yet reported. In this work, the direct energy deposition-arc (DED-arc) with and without in-situ hot forging was used to determine the microstructure evolution and mechanical properties. No internal defects were seen on the parts produced. Hot forging combined with DED-arc was seen to reduce and homogenize the grain size, improve mechanical strength and isotropy of mechanical properties. Moreover, the use of this novel DED-arc variant was seen to reduce the magnitude of residual stresses throughout the fabricated part. We highlight that this alloy can be processed by DED-arc, and the hot forging operation concomitant with the material deposition has beneficial effects on the microstructure refinement and homogenization.