Microstructure and properties of Al–7Si–0.6Mg alloys with different Ti contents deposited by wire arc additive manufacturing

Abstract

Numerous studies have addressed the advantages of wire arc additive manufacturing for manufacturing aluminum alloys. However, the role of Ti content in aluminum alloys has rarely been discussed. Herein, the effect of Ti content on the microstructure and properties of Al–7Si–0.6Mg alloys was studied. The alloys were deposited via wire arc additive manufacturing and were examined through optical microscopy (OM), scanning electron microscopy (SEM), and electronic universal testing. The results show that the increase of Ti content gradually promotes the increase of the secondary dendrite arm spacing and also has an increasing tendency to form pores defect in the as-deposited alloys. The change of titanium content also affects the difference between horizontal and vertical direction properties of the alloy. The alloy with a Ti content of 0.112 wt% exhibits the best comprehensive properties. There is no difference in its horizontal and vertical direction properties. The tensile strengths, yield strengths, and elongation of this alloy (T6) along the vertical and horizontal axis are 356 and 355 MPa, 307 and 308 MPa, and 8.5% and 8.0%, respectively.