Application of diffusion bonding model to superplastic gamma-TiAl alloys

作者：Wang, XF; Luo, ZC; Yu, GS; Lin, JG^*

来源：Materials Science and Technology, 2006, 22(2): 186-192.

DOI：10.1179/174328406X83914

• gamma-TiAl alloys
• superplasticity
• diffusion bonding
• theoretical model

In the present work, the superplastic characteristics of some gamma-TiAl alloys were analysed on the bases of experimental data reported in previous work, and their suitability for diffusion bonding was examined. The constitutive equation : epsilon = A DGb/kT (b/d)(p) (sigma-sigma 0/G)(n) can be used to describe superplasticity in gamma-TiAl alloys, and the equation predicts n=2, p=2, and activity energy Q=220 kJ mol(-1). It is suggested that the diffusion bonding model for gamma-TiAl alloys should be considered two stages, i.e. a plastic deformation stage and a void shrinkage stage including both a diffusion controlled process and a plastic controlled process. Theoretical predictions for obtaining good bonding conditions were in good agreement with experimental results. Using a theoretical bonding model, a prediction map showing the relationship among temperature, applied stress and time for high quality diffusion bonding of superplastic gamma-TiAl alloys was obtained.

• 出版日期2006-2
• 单位湘潭大学