ZrW2O8/ZrO2 composites by in situ synthesis of ZrO2 + WO3: Processing, coefficient of thermal expansion, and theoretical model prediction

The in situ synthesis of WO3 and ZrO2 in a particular mass ratio enables us to produce ZrW2O8, a material with negative coefficient of thermal expansion (CTE). By increasing the proportion of ZrO2, the products were made into a wide variety of ZrW2O8/ZrO2 composites. The temperature dependences of the CTEs of those materials were measured and the experimental data were compared with the predictions from several models. The Levin model yielded the predictive values most close to the experimental CTEs. This was the first time the micromechanics models were applied to predict the CTEs of composite materials containing a negative thermal expansion material. A ZrW2O8/ZrO2 composite with a designed CTE can be fabricated and utilized to meet a special thermal requirement in many industrial applications.