脉冲电子束对晶态金属材料表面改性的各向异性现象及其机理研究

项目名称： 脉冲电子束对晶态金属材料表面改性的各向异性现象及其机理研究

项目编号： No.51271121

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 邹建新

作者单位： 上海交通大学

项目金额： 80万元

中文摘要： 强流脉冲电子束是一种新型材料表面改性技术，它能够在微秒级内将高密度能量输入材料表层，从而诱发一系列非平衡的物理/化学过程来实现特殊的表层改性效果。研究发现，脉冲电子束对金属表层的改性可分为未熔、熔化和蒸发三种处理模式，而三种模式下均发现金属表层晶粒随其取向不同呈现特殊形变和生长现象，可在不改变材料宏观形状的条件下实现表层织构转变。在总结以往研究结果的基础上，本项目从脉冲电子束与金属材料相互作用随晶粒取向的各向异性出发，建立与晶体取向相关的温度场和应力场理论模型并进行数值模拟；在三种模式下处理几种典型的单晶和多晶金属材料，采用EBSD和TEM手段从表面和截面分析被处理材料，深入研究脉冲电子束诱发的各向异性形变和生长现象与晶粒取向及金属晶体对称性的关系，并结合温度场与应力场计算从本质上揭示脉冲电子束与金属材料相互作用的各向异性现象的机制，研究结果将进一步深化高能脉冲束流与材料交互作用的理论。

中文关键词： 强流脉冲电子书；表面改性；各向异性；温度场；形变

英文摘要： High current pulsed electron beam (HCPEB) is a newly developed technique for surface modifications of materials. It can introduce high density energy into the surface layer of treated materials within microseconds, thus resulting in a series of nonequilibrium physical/chemical processes. Thereby, special surface modification effects can be achieved. Previous investigations showed that HCPEB treatments on metal surfaces have 3 treatment modes, namely, heating, melting and evaporating modes. Under all treatment modes, irregular deformations and grain growth phenomena were observed in the surface layer. As a result, the texture in the surface layer can be modified without changing the shape of the treated materials.Based on the previous experimental and theoritical investigations, the present work attempts to build physical models of orientation dependent temperature and stress fields according to the anisotropic interactions between the electron beam and metal grains. Meantime, several typical single crystalline and polycrystalline metals will be treated by HCPEB under different treatment modes. The treated materials will be investigated from both surface and cross section views by using EBSD and TEM techniques. This is to find the relationships of electron beam generated anisotropic deformations and grain growth

英文关键词： High current pulsed electron beam；Surface modification；Anisotropy；Temperature field；Deformation