High-Pressure Shock Behavior of WC and Ta2O5 Powders

摘要

Planar shock experiments were conducted on granular tungsten carbide (WC) and tantalum oxide (Ta(sub 2)O(sub 5)) using the Z machine and a 2-stage gas gun. Additional shock experiments were also conducted on a nearly fully dense form of Ta(sub 2)O(sub 5). The experiments on WC yield some of the highest pressure results for granular materials obtained to date. Because of the high distention of Ta(sub 2)O(sub 5), the pressures obtained were significantly lower, but the very high temperatures generated led to large contributions of thermal energy to the material response. These experiments demonstrate that the Z machine can be used to obtain accurate shock data on granular materials. The data on Ta(sub 2)O(sub 5) were utilized in making improvements to the P-(lambda) model for high pressures; the model is found to capture the results not only of the Z and gas gun experiments but also those from laser experiments on low density aerogels. The results are also used to illustrate an approach for generating an equation of state using only the limited data coming from nanoindentation. Although the EOS generated in this manner is rather simplistic, for this material it gives reasonably good results.