Preparation and mechanical properties of β-Zr2O(PO4)2: A soft and damage tolerant ceramic with machinability and good thermal shock resistance

Damage tolerant and easily machinable ceramics play important roles in the field of thermal sealing and insulation. Herein, a soft and machinable beta-Zr2O(PO4)(2) ceramic with excellent thermal shock resistance is reported through detailed investigation on its mechanical properties. beta-Zr2O(PO4)(2) exhibits low hardness (5.9 GPa), low Pugh's ratio (G/B = 0.36) and good thermal shock resistance. It also can be machined by WC tools and tolerant to damage. The damage tolerance is demonstrated by the residual strength versus indentation load curve as well as the load-displacement curve during compression strength test. From the crystal structure point of view, the mechanism that underpins the damage tolerance of beta-Zr2O(PO4)(2) is the anisotropic chemical bonding within the crystal structure, which results in low and anisotropic shear deformation resistance. The possible slip systems of beta-Zr2O(PO4)(2) are (010)[100] and (100)[010].