形状记忆合金强化析出相应力状态演变规律的原位同步辐射研究

项目名称： 形状记忆合金强化析出相应力状态演变规律的原位同步辐射研究

项目编号： No.11305008

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 从道永

作者单位： 北京科技大学

项目金额： 28万元

中文摘要： 形状记忆合金强化析出相所致应力场在相变过程中的演变规律是一重要科学问题。同步辐射X射线衍射技术分辨率高、穿透能力强，能够原位追踪外场作用下晶体结构和应力状态的演化，有望解决这一基本科学问题。本项目拟以NiTi基形状记忆合金为研究对象，围绕强化析出相应力状态演变规律，建立同步辐射X射线衍射技术应用于形状记忆合金相变过程中晶体结构与微结构（晶体取向分布、应力状态等）原位表征的新方法与定量分析模式；揭示相变（R相相变、马氏体相变）过程中基体与析出相内部应力状态的演变规律，阐明析出相对低温相（R相、马氏体相）力学性能、相变温度、变体选择影响的内在微观机制并建立相应的物理模型，以期为开发高性能形状记忆材料提供理论指导。

中文关键词： 同步辐射X射线衍射；形状记忆合金；强化析出相；应力；马氏体相变

英文摘要： It remains an important scientific problem how the stress field induced by precipitation in shape memory alloys evolves during phase transformations. Synchrotron X-ray diffraction technique, which has high spatial resolution and high penetration capability, can be used for in situ tracking the evolution of crystal structure and stress state under external fields simultaneously and promises to solve this basic scientific problem. Focusing on the evolution mechanism of the stress field induced by precipitation in NiTi-based shape memory alloys, on one hand this project aims to establish the new methodology and quantitative analysis mode of using synchrotron X-ray diffraction technique to in situ characterize the crystal structure and microstructure (crystallographic orientation distribution, stress state, etc.) of shape memory alloys during phase transformations. On the other hand, this project also aims to disclose the evolution of stress state of both matrix and precipitates during phase transformations (R phase transformation and martensitic transformation) and to elucidate the underlying micro-mechanisms that are responsible for the influence of precipitates on mechanical properties of low-temperature phases (R phase and martensite), phase transformation temperatures and variant selection and establish the cor

英文关键词： In-situ synchrotron X-ray diffraction；Shape memory alloys；Strengthening precipitate；Stress；Martensitic transformation