The effect of microstructure on the shock behaviour of γ-titanium aluminides

Plate impact experiments have been performed on two alloys based on the intermetallic compound TiAl. Previously, workers have shown that microstructural features (such as grain size and phase distribution) significantly affect the mechanical response both at quasi-static and intermediate strain-rates (Hopkinson bar). In this paper, the effects of such microstructural features are extended into the shock-loading regime. In particular, the microstructural effects upon the Hugoniot, the Hugoniot Elastic Limit and the shock induced shear strength are explored. Results show that the differences in the properties of these two alloys under shock loading can be explained in terms of the microstructural differences observed at lower strain-rates.