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

Manganin stress gauges have been placed in samples of a gamma-titanium alum inide ahoy in such orientation that renders them sensitive to the lateral c omponent of stress during one-dimensional shock loading. The impact stresse s 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 m aterial. In combination with the longitudinal stress data, it has been poss ible to use the lateral stresses from this series of experiments to calcula te the shear strength during shock loading. The Hugoniot of the gamma-titan ium 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 alum inide ahoy displays a significant degree of hardening with increasing shock stress.