Decomposition of ZrW2O8 in Al matrix and the influence of heat treatment on ZrW2O8/Al–Si thermal expansion

Fully dense 64 vol.% ZrW2O8/Al–Si was fabricated by squeeze-casting technology. The decomposition of ZrW2O8 in the Al matrix was studied based on heat-treatment results. The decomposition temperature in the Al matrix is around 410 °C—far below the value for decomposition in air. A large amount of the high-pressure phase, γ-ZrW2O8, was formed due to the large stress mismatch between ZrW2O8 and Al–Si matrix. Low heat-treatment temperatures and suitable holding times can effectively limit the amount of γ-ZrW2O8 that forms as well as stopping the decomposition of ZrW2O8.