Abstract
A serious of diffusion bonding (DB) tests between high Nb containing TiAl alloy and Ti 2 AlNb alloy were conducted and the bonded joints were post-bonded heat treated (PBHT) at 1000 °C for 10h. The microstructure observation showed that the thickness and microstructure of the bonding interface were changed with the bonding parameters. The optimized parameter for direct solid-state DB high Nb containing TiAl to Ti 2 AlNb alloy was obtained as 1000°C-20MPa-90min. PBHT at 1000 °C/10h can significantly promote elements diffusion, phase transformation and microstructure evolution in bonding interface. The tensile results showed that PBHT can remarkably improve the tensile strength of TiAl/Ti 2 AlNb joints. After PBHT, the tensile strength can be increased from 80% to 146% compared with TiAl alloy by changing the failure mode. However, the Al(Nb,Ti) 2 phase in the bonding interface can't eliminated by PBHT in this study. This work provides a strategy not only contributing to control the structure of bonding interface during DB and after PBHT but also improving the properties of TiAl/Ti 2 AlNb joints.
| Original language | English |
|---|---|
| Pages (from-to) | 140-148 |
| Number of pages | 9 |
| Journal | Vacuum |
| Volume | 164 |
| DOIs | |
| State | Published - Jun 2019 |
Keywords
- Diffusion bonding
- High Nb containing TiAl alloy
- Mechanical properties
- Microstructure evolution
- Ti AlNb alloy