Preparation and properties of ZrP2O7 matrix composites with high silica fibers reinforcement

Abstract

AbstractZrP2O7 ceramics exhibit poor mechanical properties after firing, as a major drawback. In this study, ZrP2O7 matrix composites reinforced with high silica fibers were prepared through pressureless sintering by varying the content and length‐to‐diameter ratio of the high silica fibers added to ZrP2O7 powder. After heat treatment at 1200‒1300°C, the room temperature flexural strength of the ZrP2O7 matrix composites with different amounts high silica fibers having different aspect ratios was 14.9‒45.2 MPa, the bulk density was 1.90‒3.03 g·cm−3, the apparent porosity was 2.37%‒39.39%, and the room temperature thermal conductivity was .47‒.95 W/(m·K). With an increase in the heat‐treatment temperature, driven by sintering and fiber crystallization, strength of the interfacial layer between the fibers and the matrix inside the ZrP2O7 matrix composites decreased and then increased. The transfer and blocking effects of the interface enabled effective transfer of the stress of the matrix to the fiber‐reinforced phase and prevented crack extension. The problem of inherent crystallization affecting high silica fibers at high temperatures was relieved by the ZrP2O7 ceramic matrix composites.