点阵切变基体中颗粒的弹性变形行为研究

项目名称： 点阵切变基体中颗粒的弹性变形行为研究

项目编号： No.51471187

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 郝世杰

作者单位： 中国石油大学（北京）

项目金额： 85万元

中文摘要： 增强相（颗粒、纳米线等）的弹性应变与其复合材料的力学性能密切相关，然而，其在复合材料中的弹性应变较小。例如，单体态纳米线具有超大弹性应变（4-7%），但其在复合材料中的弹性应变却有限（小于1.8%）。最近，我们发现点阵切变基体中纳米线呈现超大弹性应变，但此类纳米线复合材料存在组元体系受限等问题，若采用常规析出或球化方法获得的颗粒具有大弹性应变，则可望获得广泛应用。为此，我们最近探索了点阵切变基体中颗粒的弹性变形行为，初步发现，点阵切变NiTi基体中析出颗粒（Ti3Ni4）与球化颗粒（Nb）呈现的弹性应变均远大于其在位错滑移基体中呈现的弹性应变，且呈现了弹性变形的瞬时性、弹性应变分布非均匀性、弹性应变松弛等特征。本项目拟揭示点阵切变基体中颗粒呈现大弹性变形的瞬时性、弹性应变分布非均匀性、弹性应变松弛等特征、机制及影响因素，阐明其弹性变形与基体切变变形之间的内在联系，可望获得高质量学术成果。

中文关键词： 点阵切变；弹性变形；颗粒；形状记忆合金

英文摘要： Elastic strain of reinforcements (particles, nanowires) is closely related to the mechanical properties of composites, but the elastic strain of reinforcements is smaller in composites. For example, freestanding nanowires have ultra-large elastic strain (4-7%), but its elastic strain in composites is limited (less than 1.8%). Recently, we found that the nanowires embedded in the matrix deformed by lattice shear showed ultra-large elastic strain, but the component systems of such nanowire composites are limited. If the particles formed by conventional aging or spheroidizing methods have large elastic strain, it is expected to be widely available. To this end, we have recently explored the elastic deformation behavior of the particles embedded in the matrix deformed by lattice shear. The preliminary findings as follows: the precipitation particles (Ti3Ni4) and spherical particles (Nb) in the NiTi matrix deformed by lattice shear show much larger elastic strain than that in the matrix deformed by dislocation slip, and present the elastic deformation instantaneity, elastic strain distribution non-uniformity, elastic strain relaxation and other characteristics. This project intends to reveal the characteristics, mechanisms and factors of the large elastic deformation instantaneity, elastic strain distribution non-uniformity and elastic strain relaxation of the particles in the matrix deformed by lattice shear, and to clarify the intrinsic link between the elastic deformation of particles and the lattice shear deformation of matrix. It is expected to obtain high-quality academic achievement.

英文关键词： Lattice shear;Elastic deformation;Particles;Shape memory alloy