Despite the vast applications of transformable ceramics, such as zirconia-based ceramics, in different areas from biomedical to aerospace, the fundamental knowledge about their mechanical degradation procedure is limited. The interaction of the phase transformation and crack growth is crucial as the essential underlying mechanism in fracture of these transformable ceramics, also known as shape memory ceramics. This study develops a three-dimensional (3D) multiphysics model that couples the variational formulation of brittle crack growth to the Ginzburg-Landau equations of martensitic transformation. We parameterized the model for the 3D single crystal zirconia, which experienced stress- and thermal-induced tetragonal to monoclinic transformation. The developed 3D model considers all 12 monoclinic variants, making it possible to acquire realistic microstructures. Surface uplifting, self-accommodated martensite pairs formation, and transformed zone fragmentation were observed by the model, which agrees with the experimental observations. The influence of the crystal lattice orientation is investigated in this study, which reveals its profound effects on the transformation toughening and crack propagation path.

尽管可转化陶瓷（如氧化锆基陶瓷）在生物医学和航空航天等不同领域有着广泛的应用，但对其机械降解过程的基础知识是有限的。相变和裂纹扩展的相互作用作为这些可变形陶瓷（也称为形状记忆陶瓷）断裂的基本潜在机制至关重要。本研究开发了一个三维 (3D) 多物理场模型，该模型将脆性裂纹扩展的变分公式与马氏体转变的 Ginzburg-Landau 方程相结合。我们参数化了 3D 单晶氧化锆的模型，该模型经历了应力和热诱导的四方向单斜转变。开发的 3D 模型考虑了所有 12 个单斜变体，使获得逼真的微观结构成为可能。模型观察到地表隆升、自容马氏体对形成和转化带破碎，与实验结果一致。本研究研究了晶格取向的影响，揭示了其对相变韧化和裂纹扩展路径的深远影响。