Peridynamic simulations of the tetragonal to monoclinic phase transformation in zirconium dioxide
Peridynamic simulations of the tetragonal to monoclinic phase transformation in zirconium dioxide
复制标题
二氧化锆中四方相到单斜相变的近场动力学模拟
DOI：
10.1016/j.commatsci.2017.09.001
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发表时间：
2017
影响因子：
3.3
通讯作者：
Platt P
中科院分区：
文献类型：
--
作者：
Platt P
无论是作为制造的稳定陶瓷，还是作为锆合金上的氧化物层，氧化锆的机械降解都受到四斜晶系到单斜晶系相变的影响。在Abaqus有限元框架内实施周晶理论，以了解四方晶到单斜晶相变本身如何导致氧化锆断裂。在2D中，这些模拟代表了一个单一的晶粒，通过等轴扩张膨胀转变，周围是均匀的单斜氧化物。使用应变能的变化和周围的氧化物中的损伤量的转变时间，施加的双轴向压力，和断裂应变的效果进行了评估。减小所施加的压缩应力或施加拉伸应力减小了转变应变能。断裂应变的引入导致周围氧化物区域中的损伤主要以裂纹的形式，并且通过减少对转变晶粒的约束而进一步减少转变应变能。的断裂程度，并减少约束的转化晶粒，是更显着的应用程序的双向拉伸压力。
Whether present as a manufactured stabilised ceramic, or as an oxide layer on zirconium alloys, mechanical degradation in zirconia is influenced by the tetragonal to monoclinic phase transformation. Peridynamic theory was implemented within the Abaqus finite element framework to understand how the tetragonal to monoclinic phase transformation can itself cause fracture in zirconia. In 2D these simulations represent a single grain, transforming via an isometric dilational expansion, surrounded by a homogenous monoclinic oxide. The effect of transformation time, applied bi-axial pressure, and the fracture strain were assessed using the change in strain energy and the amount of damage in the oxide surrounding the transformed grain. Reducing the applied compressive stress or applying a tensile stress reduces the transformation strain energy. The introduction of a fracture strain leads to damage in the surrounding oxide region largely in the form of cracks, and reduces the transformation strain energy further by reducing the constraint on the transforming grain. The extent of the fracture, and reduction in constraint on the transformed grain, is more significant with the application of a biaxial tensile pressure.