Release Time:2019-07-01  Hits:

Indexed by: Journal Article

Date of Publication: 2019-03-01

Journal: WELDING IN THE WORLD

Included Journals: EI、SCIE

Volume: 63

Issue: 2

Page Number: 323-336

ISSN: 0043-2288

Key Words: Vacuum brazing; Ti-Zr-Cu amorphous filler metal; Interfacial microstructure; Intermetallic compound (IMC); Shear strength

Abstract: TC4 titanium alloy was vacuum-brazed to 316L stainless steel (SS) with Ti-Zr-Cu amorphous filler metal. The effect of brazing time and temperature on the interfacial microstructure and mechanical properties of joints was investigated. Electron probe micro-analyzer (EPMA) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) were used to study the joint microstructure; meanwhile, the reaction phases on fracture surfaces were identified by X-ray diffraction (XRD). The results show that all joints had similar interfacial microstructure of TC4 titanium substrate/Widmanstatten/-Ti + Ti2Cu/(-Ti + -Cu2TiZr) + Ti2Cu/Ti-Fe-Cu/TiFe/(Fe, Cr)(2)Ti/sigma-phase + Fe-ss/316L stainless steel substrate. Three reaction layers TiFe/(Fe, Cr)(2)Ti/sigma-phase + Fe-ss formed close to 316L stainless steel substrate and could benefit the mechanical properties of joints. The maximum shear strength of 65MPa was obtained at 950 degrees C for 10min. During shear test, cracks initiated at the interface of Ti-Cu-Fe layer/TiFe layer and propagated along the brazed seam/316L interface with a large amount of cleavage facets existing on the fracture surface.