Mechanical and microstructure characteristics of 7475-T7351 aluminium alloy joints welded by robot cold metal transfer

Abstract

The purpose of this research is to analyse the microstructural parameters, as well as mechanical properties of robotic CMT, welded AA7475-T7351 alloy. The welded joint’s morphology and evolution, as well as its mechanical properties and also fracture behaviour, were studied. In contrast to the weld, the base metal carries the maximum tensile strength. The weld metal (WM) has the lowest hardness, just 58.24% of the base metal (BM). The general microstructure of the weld area was studied for the welded joint. Weld fractography revealed a high number of equiaxed dimples uniformly spread over the fracture surface, as evidenced by scanning electron microscopy (SEM) micrographs and a corresponding energy dispersive X-ray (EDX) of the weld.