Steady-state creep of metal-ceramic multilayered materials
Steady-state creep of metal-ceramic multilayered materials
复制标题
DOI：
10.1016/1359-6454(95)00294-4
复制
发表时间：
1996-04
期刊：
影响因子：
9.4
通讯作者：
Yu‐Lin Shen;S. Suresh
中科院分区：
文献类型：
--
作者：
Yu‐Lin Shen;S. Suresh
本文提出了一种分析金属陶瓷多层膜在温度单调或循环变化下稳态蠕变响应及其机理的一般方法。这种方法结合了连续介质力学的板或梁理论和稳态蠕变的基于力学的经典本构方程。该方法是能够预测的分层固体中的整体曲率的演变，在每一层内的热应力的产生，以及在任何时刻的时间或温度的每一层的任何厚度位置处的主要变形机制，对于规定的层的几何形状，热机械性能的组成层，和所施加的热历史。对Al → Al_2O_3双层和Al_2O_3 → Al → Al_2O_3三层模型系统进行了模拟。预测结果与适当的实验测量的双层进行热循环高达450°C。据发现，多层蠕变计算捕获的循环热响应的基本特征，在铝层的应力松弛的程度，但是，有点高估，特别是在较高的温度下。这种差异的可能原因进行了讨论，并强调了整体方法的意义和局限性。加热或冷却速率对变形的影响，以及本蠕变分析和速率无关的弹塑性配方的多层之间的相关性也被认为是。层厚度的蠕变机制的演变的影响也检查从厚多层的限制情况下的薄金属膜上的脆性基板。
A general approach is presented for analyzing the steady-state creep response and its underlying mechanisms in metal-ceramic multilayers subjected to monotonic or cyclic variations in temperature. This approach combines the plate or beam theories of continuum mechanics with the mechanism-based classical constitutive equations for steady-state creep. The method is capable of predicting the evolution of overall curvature in the layered solid, the generation of thermal stresses within each layer, and the dominant deformation mechanisms at any through-thickness location of each layer at any instant of time or temperature for prescribed layer geometries, thermo-mechanical properties of the constituent layers, and the applied thermal history. Simulations are presented for AlAl2O3bilayer and Al2O3AlAl2O3trilayer model systems. The predicted results are compared with appropriate experimental measurements for the bilayers subjected to thermal cycling up to 450°C. It is found that the multilayer creep calculations capture the essential features of cyclic thermal response; the extent of stress relaxation in the Al layer, however, is somewhat overestimated, especially at higher temperatures. Possible reasons for such discrepancy are discussed, and the significance and limitations of the overall approach are highlighted. The effects of the rate of heating or cooling on deformation, and the correlations between the present creep analyses and rate-independent elastoplastic formulations for multilayers are also considered. The influence of layer thickness on the evolution of creep mechanisms is also examined from thick multilayers to the limiting case of a thin metallic film on a brittle substrate.