Diffusion Interface Evolution of Low-Alloy Steel Q235 and Ti by Electro-Assisted Hot-Pressing Bond

In this study, the low-alloy steel (Q235) and commercially pure titanium (TA1) were joined by an electro-assisted hot-pressing process in a low temperature range of 700–850°C with an axial load of 10 MPa. At the same time, a conventional hot-press diffusion process without electro-assistance was also carried out, which was used to elucidate the effect of the current on element diffusion. Based on the thickness of the interface layer, the interlayer growth kinetics and activation energy under two processes were calculated. The results revealed that the presence of an electric current significantly enhanced elemental diffusion. The growth activation energy of the TiC layer from electrically-assisted hot pressing (EAHP) and hot pressing (HP) were 137.37 kJ/mol and 190.29 kJ/mol, respectively. At 800°C, the maximum tensile shear strength of the joint produced by the electrically-assisted hot-pressing process was 214.5 MPa, while the value of the joint formed by conventional hot pressing was 139.7 MPa.