Lateral stress measurements and shear strength in a shock-loaded γ-TiAl alloy

Manganin stress gauges have been placed in samples of a gamma-titanium aluminide ahoy in such orientation that renders them sensitive to the lateral component of stress during one-dimensional shock loading. The impact stresses were in the range 1.8 to 6 GPa. The resultant stress histories show clear evidence of a transition from elastic to plastic behaviour, which, through the elastic relations correlates with the Hugoniot Elastic Limit of this material. In combination with the longitudinal stress data, it has been possible to use the lateral stresses from this series of experiments to calculate the shear strength during shock loading. The Hugoniot of the gamma-titanium aluminide studied is seen to be significantly different than a standard alpha-beta Ti-alloy such as Ti-6Al-4V. The results show this titanium aluminide ahoy displays a significant degree of hardening with increasing shock stress.