Effect of Isothermal Deformation Amount on Electron Beam Welded Joint of Ti60/Ti-22Al-25Nb

Abstract

Ti60 and Ti-22Al-25Nb were joined by an electronic beam (EB) welding then forged by a microprocessor-controlled 630 ton hydraulic press at different deformation amounts (30%, 40%, and 50%). The effect of the deformation amount on the microstructure and properties of the welded joint of Ti60/Ti-22Al-25Nb during isothermal forging was investigated. The results revealed that the samples exhibited great strength, which was insensitive to the microstructure because of the high τ p . It was found that the elongation (A) and reduction of area (Z) were strongly dependent on microstructural features. Ductility was greatly improved by the 40% and 50% deformation. Furthermore, the 40% deformation sample exhibited the greatest combination of strength and ductility.

Microstructure Control of Welded Joints of Dissimilar Titanium Alloys by Isothermal Forging

“…Meanwhile, many second phases were precipitated in the grain. From Figure 5, note that after isothermal forging the welded joint is composed of the matrix B2 phase, the O phase, and α2 phase [21]. The α2 phase is the darkest, and is lath-shaped or globular, and the matrix B2 phase is the lightest.…”

“…Therefore, it can be deduced that 1010 °C is higher than the phase transition point of the welded joint, and the second phase α2/O is completely transformed into B2 phase under these conditions. From Figure 5, note that after isothermal forging the welded joint is composed of the matrix B2 phase, the O phase, and α 2 phase [21]. The α 2 phase is the darkest, and is lath-shaped or globular, and the matrix B2 phase is the lightest.…”