基于整体结构的纳米晶体材料力学模型

Polycrystalline mechanical model for bulk nanocrystalline materials as an integral obeject

为了系统地分析晶粒尺寸、应变速率和缺陷对纳米晶体材料的影响,提出了1个新的本构模型,运用能量法描述纳米晶体的变形机理、微结构演变和力学行为.在模型中,晶粒和晶界作为一个整体共同承担位错和晶界滑移.通过对纳米晶体N i在不同应变速率和晶粒尺寸条件下的实验,验证改进模型的可行性.与实验数据对比发现,预测的模型可以用来描述纳米晶体材料的力学性能.

A new constitutive model was developed to describe the deformation mechanism, microstructure evolution and mechanical response of bulk nanocrystalline materials using the energy approach to systematically describe the grain size, strain rate and defect development dependent mechanical characteristic of bulk nanocrystalline materials. In this model, the grain and the grain boundary were taken as an integral object to sustain dislocation and accommodate grain boundary sliding mechanisms. Nanoerystalline Ni samples tested by different strain rates and grain sizes were prepared to test the applicability of the developed model. Compared with the experimental data, the predicted model can describe the mechanical response of bulk nanocrystalline materials.