Electro-Superplastic Solid State Welding of 40Cr/QCr0.5

Abstract

Hot-squeezed chrome bronze QCr0.5 and ultra-fine treated 40Cr steel have been successfully welded using an electro-superplastic solid-state welding technique. Results have shown that the tensile strength of a 40Cr/QCr0.5 weld joint can be greatly increased, up to or exceeding that of QCr0.5 base metal. The weld interface between 40Cr and QCr0.5 has achieved metallurgical bonding and there are less micro-gaps, thicker transition regions and more copper convexes and dimples on the fracture surface of the 40Cr side when applying an external electrical field of E = 3 kV/cm, as well as with other welding parameters, including no vacuum, no shield gas, a pre-pressure of 56.6 MPa, an initial strain rate of 1.5 × 10−4 s−1, a pressure welding temperature of 710–800 °C, and a pressure welding time of 0–8 min.

Effects of deformation conditions on the superplastic deformation behavior of LZ91 Mg-Li alloy under electric field

“…They found that the elongation is increased from 5% to 135% after applying 120 V/cm 2 DC to ceramic materials. Wang et al [4] who successfully welded copper and steel alloys under an external electric field, demonstrated that electric fields can enhance superplasticity.…”