Effect of post-weld heat treatment on the interface microstructure of explosively welded titanium–stainless steel composite

In this study, the interface microstructure evolutions of the explosively welded cp-Titanium/AISI 304 stainless steel composites due to heat treatment are presented. The composites were subjected to heat treatment process at temperature ranges of 650–950 °C in argon atmosphere for 1 h. The investigations were carried out by using optical microscopy (OM), scanning electron microscopy (SEM). The results reveal the presence of reaction layers in the diffusion zone. The compositions of the reaction products were determined by energy dispersive spectroscopy (EDS). Furthermore, the composition–penetration plots for Ti, Fe, Cr and Ni across the interface were obtained from EDS microanalysis. Concentration of discontinuities in the profiles indicating the formation of intermetallics in the diffusion zone that were also detected by X-ray diffraction (XRD) method, on the Ti-side of fractured surfaces. The results show that post-heating of the composite layers in these temperatures causes to form different intermetallic phases at the joint interface. Moreover, post-heating increases the width of interfacial layers of the composite.