Adjustable Thermal Expansion Properties in Zr2MoP2O12/ZrO2 Ceramic Composites

• Main Authors: Hongfei Liu, Weikang Sun, Xiang Xie, Lu Yang, Zhiping Zhang, Min Zhou, Xianghua Zeng, Xiaobing Chen
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2018-08-01
• Series: Frontiers in Chemistry
• Subjects: ceramics; Zr2MoP2O12; ZrO2; composites; thermal expansion control
• Online Access: https://www.frontiersin.org/article/10.3389/fchem.2018.00347/full

Zr2MoP2O12/ZrO2 composites were successfully synthesized by the solid state method in attempt to fabricate the near-zero thermal expansion ceramics. The phase composition, micromorphology and thermal expansion behavior of the Zr2MoP2O12/ZrO2 composites with different mass ratios were investigated using X-ray diffraction, scanning electron microscopy and thermal mechanical analysis. Results indicate that Zr2MoP2O12/ZrO2 composites can be prepared by pre-sintering at 500°C for 3 h and then sintering at 1050°C for 6 h. The resulting Zr2MoP2O12/ZrO2 composites consisted of orthorhombic Zr2MoP2O12 and monoclinic ZrO2. With increasing content of Zr2MoP2O12, the Zr2MoP2O12/ZrO2 ceramics became more compact and the coefficient of thermal expansion decreased gradually. Zr2MoP2O12/ZrO2 composites show an adjustable coefficient of thermal expansion (CTE) from 5.57 × 10−6 K−1 to −5.73 × 10−6 K−1 by changing the mass ratio of Zr2MoP2O12 and ZrO2. The Zr2MoP2O12/ZrO2 composite with a mass ratio of 2:1 showed near zero thermal expansion, and the average linear thermal expansion coefficient is measured to be 0.0065 × 10−6 K−1 in the temperature range from 25 to 700°C.