Impact of high-current pulsed electron beam modification on element diffusion and performance of Ti6Al4V/AISI 316 L stainless steel diffusion bonded joints

The diffusion bonding process between Ti6Al4V and 022Cr17NiMo2 stainless steel (AISI 316 L SS) was carried out under vacuum conditions, applying a 10 MPa load for 40 min within a temperature range of 800–900 °C. This study investigates the influence of high-current pulsed electron beam (HCPEB) modification on the microstructure at the interface and the shear strength of Ti6Al4V/AISI 316 L SS joints. After HCPEB pretreatment, a well-formed diffusion bond was achieved between Ti6Al4V and AISI 316 L SS at 900 °C. Through calculations, the diffusion coefficient and diffusion activation energy of Fe in the Ti6Al4V section were determined, which demonstrated that Fe exhibits higher diffusion rates in the HCPEB-modified joints. The modified joint, subjected to 900 °C, exhibited a maximum bond strength of 208 MPa, which is attributed to dispersion and solid solution strengthening. Consequently, the implementation of HCPEB modification proves effective in promoting element diffusion and enhancing the mechanical performance of the joints. The presence of abundant crystal defects, including vacancies, dislocations, and grain boundaries (GBs) generated by HCPEB, is believed to be responsible for the observed improvement in diffusion.