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

Abstract

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°C for 80 s, 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 s phase presented on the fracture, and on the titanium alloy side, a-Ti transformed into b-Ti in the vicinity of interface while diffusion bonding.KEY WORDS: surface self-nanocrystallization; Ti-4Al-2V; 0Cr18Ni9Ti; pluse pressuring diffusion bonding.