In-situ wire-feed additive manufacturing of Cu-Al alloy by addition of silicon

Present work investigated the use of Cold Metal Transfer (CMT) welding for additive manufacturing of copper‑aluminum alloys with addition of silicon in small amount. The additive manufacturing was successfully demonstrated through two samples with the 4.34% (sample-1) and 6.58% (sample-2) aluminum content, which is not much different with the content of the design. The analyses of performance of samples reveal that both samples have good strength and ductility. It is also found addition of silicon in small amount (2.1%–2.4%) effectively improves hardness, tensile strength and 0.2% offset Yield Strength in comparison to pure copper‑aluminum alloy. The results of X-ray diffraction (XRD), showed that sample-2 possessed CuAl2 with different crystal structure whereas sample-1 did not. It is found that an increase in aluminum caused both tensile strength and 0.2% offset Yield Strength to increase, however, increase in yield strength was very significant (155 MPa i.e. 38% more than that of Sample-1). In this study, the 0.2Pct offset Yield Strength of sample-1 is 150 MPa more than that of sample-2.