A multiscale modelling analysis of the contribution of crystalline elastic anisotropy to intergranular stresses in ferroelectric materials
A multiscale modelling analysis of the contribution of crystalline elastic anisotropy to intergranular stresses in ferroelectric materials
复制标题
DOI：
10.1088/0022-3727/47/32/325303
复制
发表时间：
2014-07
期刊：
影响因子：
--
通讯作者：
Laurent Daniel;David Hall;P. J. Withers
中科院分区：
文献类型：
--
作者：
Laurent Daniel;David Hall;P. J. Withers
内部应力（残余应力）及其在机电载荷下的演化对铁电材料的性能和寿命起着重要作用。制造过程或包装条件可引起内应力。在更精细的尺度上，由于铁电材料的异质性（多晶结构），部分铁电应变通常必须局部适应，从而在施加机电负载时产生内应力。在大多数建模方法中，晶体弹性各向异性对内应力的贡献被忽略，而不是域切换的贡献。使用微观力学建模的方法，我们研究的贡献晶体弹性各向异性的宏观行为和内部应力分布在铁电多晶体机电负载下。它表明，预测的宏观铁电应变和晶间应力的水平可以低估高达50%，如果忽略晶体弹性各向异性。因此，建议，与目前的做法相反，晶体各向异性包括在铁电陶瓷的微观力学建模。
Internal stresses (residual stresses) and their evolution under electromechanical loading play a significant role in the performance and lifetime of ferroelectric materials. Internal stresses can be induced by the manufacturing process or the packaging conditions. At a finer scale, due to the heterogeneity of ferroelectric materials (polycrystalline structure), part of the ferroelectric strain must normally be accommodated locally, resulting in internal stresses when an electromechanical load is applied. In most modelling approaches the contribution of crystalline elastic anisotropy to internal stresses is neglected compared to the domain switching contribution. Using a micromechanical modelling approach, we examine the contribution of crystalline elastic anisotropy to the macroscopic behaviour and to the internal stress distribution in ferroelectric polycrystals under electromechanical loading. It is shown that the predicted macroscopic ferroelectric strain and the level of intergranular stress can be underestimated by up to 50% if crystalline elastic anisotropy is neglected. Consequently it is recommended that, contrary to current practice, crystalline anisotropy be included in the micromechanical modelling of ferroelectric ceramics.