Electron beam welding process of BT5-1 titanium alloy and C-103 niobium alloy

C103 niobium alloy is a new niobium alloy with better welding and forming properties than other niobium alloys. It can meet the needs of rocket engine parts with operating temperature of 1480℃. It is a new generation alloy for aerospace propulsion system. The cost of the communication satellite rocket booster made of C103 niobium alloy is obviously reduced due to its reduced weight and improved reliability.

Titanium alloy has low density, high specific strength and good thermal strength. Bt5-1 titanium alloy can work at a long time temperature of up to 723 K, which is often used in the aerospace field of high temperature resistant structural parts. Electron beam welding of BT5-1 titanium alloy and C103 niobium alloy is of great significance in satellite rocket, space station and other aerospace fields. (1) The joint of BT5-1 titanium alloy and C103 niobium alloy connected by appropriate electron beam welding procedure specification is well formed without cracks and other defects.

(2) When the duty ratio of C103 niobium alloy is small, the fusion width of BT5-1 titanium alloy side is large, but the fusion depth is small, and C103 niobium alloy has no penetration. When the duty ratio of C103 niobium alloy is large, the fusion width of BT5-1 titanium alloy side is relatively small, but the fusion depth is large, the weld surface is formed well, the fusion of C103 niobium alloy is sufficient, and the interface is combined well.

Based on the analysis of the properties of BT5-1 titanium alloy and C103 niobium alloy and the characteristics of electron beam welding, the electron beam welding between BT5-1 and C103 was realized. The joint between BT5-1 and C103 connected by appropriate electron beam welding procedure specification is well formed without cracks and other defects. Duty ratio has important influence on welding quality.