The response of TiAl based alloys to one-dimensional shock loading

The behaviour of two different alloys based on the intermetallic phase TiAl, with different microstructures and grain sizes have been investigated during shock loading. Significant differences in the equation of state (stress-shock velocity-particle velocity), one-dimensional yield strength and shear strength have been observed. These have been explained in terms of the microstructural differences between the two alloys. In addition, differences between the equation of state and the calculated hydrostat have been noted. An increase in the shear strength with increasing stress has been suggested, and confirmed with independent lateral stress measurements. The increase in shear strength has been explained as being due to the high work-hardening rates displayed by such materials, although an alternative possibility-the positive dependence of the shear modulus to pressure-has also been proposed. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.