Negative thermal expansion material ZrW2O8/Zr2WP2O12 composite was prepared by liquid phase sintering.The apparent density of ZrW2O8 without any sintering additive was about 3.7 g/cm3, corresponding to about73% of its theoretical density. However, the relative density of the samples, sintered with more than 5 mol%P2O5 was about 90%. The identified phases were mainly ZrW2O8 with small amounts of WO3, ZrO2 andZr2WP2O12 by XRD. The intensity of Zr2WP2O12 peaks increased with increasing P2O5 content. It wassurmised that the melting of ZrO2–P2O5 resulted in liquid phase formation, which is then converted toZr2WP2O12 on the final stage of sintering. Therefore, Zr2WP2O12 phase was observed at the gap between theZrW2O8 grains and at the triple junctions. The ceramics sintered with 20 mol% P2O5 showed a negativethermal expansion coefficient of −4.0×10−6 °C−1.
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