Pulse Pressuring Diffusion Bonding of Ti-4Al-2V/0Cr18Ni9Ti with Nanostructured Layer Synthesized by Surface Self-nanocrystallization

Nanostructured surface layer was synthesized on the end face of Ti-4Al-2V alloy and 0Cr18Ni9Ti austenite stainless steel rods by means of Surface self-nanocrystallization(SSNC). Making treated end surfaces as bonding interfaces, transition joint of Ti-4Al-2V alloy and 0Cr18Ni9Ti stainless steel bars was prepared by pluse pressuring diffusion bonding (PPDB) on Gleeble-1500D tester at 850 degrees C for 80s, the maximum and minimum pluse pressuring were 8 MPa and 50 MPa respectively, and cycle (N) and frequency (f) of pulse load were 40 times and 0.5 Hz respectively. Bonded joints were tensed on CMT5105 style instron. Microstructure of transition joint was investigated by scanning electron microscope (SEM) and X-ray energy dispersive spectroscope (EDS). The reaction products on the fracture were detected using X-ray diffraction (XRD). Research results showed that the maximum tensile strength reached 384.0 MPa, cleavage fracture took place while tension test of joints. Brittle intermetallic compounds such as Fe(2)Ti, FeTi and sigma phase presented on the fracture, and on the titanium alloy side, alpha-Ti transformed into beta-Ti in the vicinity of interface while diffusion bonding.