Synthesis of Zr 2 WP 2 O 12 /ZrO 2 Composites with Adjustable Thermal Expansion.

Zr2 WP2 O12 /ZrO2 composites were fabricated by solid state reaction with the goal of tailoring the thermal expansion coefficient. XRD, SEM and TMA were used to investigate the composition, microstructure, and thermal expansion behavior of Zr2 WP2 O12 /ZrO2 composites with different mass ratio. Relative densities of all the resulting Zr2 WP2 O12 /ZrO2 samples were also tested by Archimedes' methods. The obtained Zr2 WP2 O12 /ZrO2 composites were comprised of orthorhombic Zr2 WP2 O12 and monoclinic ZrO2 . As the increase of the Zr2 WP2 O12 , the relative densities of Zr2 WP2 O12 /ZrO2 ceramic composites increased gradually. The coefficient of thermal expansion of the Zr2 WP2 O12 /ZrO2 composites can be tailored from 4.1 × 10-6 K-1 to -3.3 × 10-6 K-1 by changing the content of Zr2 WP2 O12 . The 2:1 Zr2 WP2 O12 /ZrO2 specimen shows close to zero thermal expansion from 25 to 700°C with an average linear thermal expansion coefficient of -0.09 × 10-6 K-1 . These adjustable and near zero expansion ceramic composites will have great potential application in many fields.