Mapping interfacial strain during mechanical loading of 316L-Ni bimetallic structure fabricated by directed energy deposition additive manuf

Bimetallic structures, a combination of two different metals, have gained broad attention in recent years because of their multifunctional properties integrated in a single structure component. The 316L-Ni bimetallic structure we produced via directed energy deposition (DED) inherits excellent corrosion resistance and biocompatibility from AISI 316L stainless steel, and high electrical and thermal conductivities from pure nickel. However, there is a sharp microstructural transition region: the grain structure is distinguished at the interface due to the sudden change in the composition. Such discontinuity brings about the fracture weakness due to the interfacial residual strain. We seek to investigate the interfacial strain field during mechanical loading of this bimetallic structure by using in situ transmission X-ray powder diffraction. Various DED parameters will be assessed, hence providing guidance to optimise the manufacturing routine for industrial and scientific community.