In this study, we developed a micromechanics scheme to predict the upper and lower bounds on the creep strain and stress relaxation induced by interface diffusion in metal-matrix particulate composites. The normal stress acting on the matrix-inclusion interface, which is the driving force for interface diffusion, is estimated by using the Hashin-Shtrikman bounds and mean-field micromechanics theory. Analytical solutions of upper and lower bounds on the creep strain under constant stress and the relaxed stress at fixed strain are obtained. Results of this work show that the ultimate creep strain and relaxed stress are only related to the material properties and the percentage of each component, such as volume fraction of inclusion and elastic modulus ratio of inclusion to matrix. The parameters of interface diffusion only influence the rate of creep strain. It is found that the creep deformation and stress relaxation of composites are more sensitive to the volume fraction of inclusion than the elastic modulus ratio. The methodology of this study also applies to analysis of creep deformation of composites where both the matrix creep and interface diffusional creep need to be considered. The present study offers new perspectives for in-depth understanding of creep behavior of composites driven by mass diffusion along inclusion-matrix interface.

在这项研究中，我们开发了一种微力学方案，以预测金属基颗粒复合材料中界面扩散引起的蠕变应变和应力松弛的上限和下限。利用Hashin-Shtrikman边界和平均场微力学理论估算作用在基体-夹杂物界面上的法向应力，即界面扩散的驱动力。获得了在恒定应力和固定应变下的松弛应力的上限和下限的解析解。这项工作的结果表明，极限蠕变应变和松弛应力仅与材料性能和每种成分的百分比有关，例如夹杂物的体积分数和夹杂物与基体的弹性模量比。界面扩散参数仅影响蠕变应变率。发现复合材料的蠕变变形和应力松弛比弹性模量比对夹杂物的体积分数更敏感。本研究的方法还适用于复合材料的蠕变变形分析，其中既要考虑基体蠕变又要考虑界面扩散蠕变。本研究为深入理解复合材料沿夹杂物-基体界面扩散引起的蠕变行为提供了新的视角。本研究的方法还适用于复合材料的蠕变变形分析，其中既要考虑基体蠕变又要考虑界面扩散蠕变。本研究为深入理解复合材料沿夹杂物-基质界面的质量扩散驱动的蠕变行为提供了新的视角。本研究的方法还适用于复合材料的蠕变变形分析，其中既要考虑基体蠕变又要考虑界面扩散蠕变。本研究为深入理解复合材料沿夹杂物-基质界面的质量扩散驱动的蠕变行为提供了新的视角。