Novel two-step sintering and in situ bonding method for fabrication of ZrP2O7 ceramics

Abstract Sintering performance at high temperatures is a serious issue for tetravalent metal pyrophosphate MP2O7 ceramics (M = Ti, Zr, Hf, Ge, Sn, etc.). Herein, we investigated the influence of high synthesis temperatures and amounts of ZrP2O7 precursors on the properties of ZrP2O7 ceramics. A ZrP2O7 powder was first synthesised via a solid-state reaction; this powder was used in the fabrication of the ZrP2O7 ceramic using a combination of two-step sintering and in situ bonding using MgO as the sintering aid. The phase composition and microstructure of the ZrP2O7 powder as well as the ZrP2O7 ceramic were studied by X-ray diffraction and scanning electron microscopy. The physical properties and room-temperature thermal conductivity of the ZrP2O7 ceramic were investigated. The ceramic exhibited high thermal stability at 1350 °C. This study indicates that the mechanical properties of the ZrP2O7 ceramic can be enhanced while maintaining their low thermal conductivity by sintering it at 1300 °C with the addition of an appropriate amount of the ZrP2O7 precursors to the ZrP2O7 powder.