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

摘要

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 degrees C far below the value for decomposition in air. A large amount of the high-pressure phase, gamma-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 gamma-ZrW2O8 that forms as well as stopping the decomposition of ZrW2O8. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.