High‐Temperature Mechanical Properties and Chemical Stability of Ba1+xZr4P6–2xSi2XO24 Low‐Thermal‐Expansion Ceramics

Abstract

The NaZr2P3O12 (NZP) family of materials is attracting increasing attention due to its low‐thermal‐expansion behavior. The system Ba1+xZr4P6–2xSi2xO24 (0 ≤x≤ 1), belonging to the NZP family, shows ultralow thermal expansion over a wide temperature range. It also shows anisotropy in its lattice thermal expansion. This causes microcracking as the sintered specimens are cooled, which results in degradation of the mechanical properties. In this work, the chemical stability, strength, and Young's modulus of Ba1+xZr4P6–2xO24 (X= 0.25 and 0.5) ceramics at high temperatures have been determined. An attempt has been made to correlate the mechanical properties to the thermal expansion anisotropy.