基于多场耦合医用钛合金α相快速再结晶及取向调控研究

项目名称： 基于多场耦合医用钛合金α相快速再结晶及取向调控研究

项目编号： No.51501150

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 邵晖

作者单位： 西安理工大学

项目金额： 20万元

中文摘要： 医用细晶钛合金的韧性较差易导致其制备的器械损伤断裂引起国内外生物材料界的关注，主要因为变形合金中存在大量晶体缺陷、微观应力和织构。同传统热处理相比，应力-电流-温度耦合处理具有快速实现再结晶和调控相取向的特点，相关机理的认识还不深入。本项目拟以变形医用细晶（α相尺寸为1～5μm，β相尺寸为0.5～1μm）Ti-6Al-4V钛合金线材为研究对象，通过研究合金的多场耦合处理，阐明空位扩散和位错运动对等轴α相快速细晶化的影响机理，确定晶界滑移致等轴α相(0001)取向密度减小程度和应力诱发次生α相取向类型；结合钛合金α相晶格间距变化，探索合金冷却收缩应力与外加恒应力的定量关系。本项目不仅会加深对快速细晶化机理和动力学的理解，而且对促进我国钛合金相取向选择的基础研究发展、优化细医用晶钛合金制备工艺都具有重要意义。

中文关键词： 多场耦合；；钛合金；再结晶；取向

英文摘要： Because of the crystal defect, texture and microstress in the fine-grained titanium alloy for medical implants from the plastic deformation, the damage and fracture caused by the poor toughness in the titanium equipment have attracted more and more attention of biological material industry at home and abroad. Compared with the conventional heat treatment, the rapid crystallization and the orientation controlling of the α phase can be controlled by the coupling effect of stress and electric and temperature field. The understanding of the relevant mechanisms should be taken into consideration deeply. In this project, biomedical Ti-6Al-4V wire (α phase size: 1～5um, β phase size: 0.5～1um ) is prepared by the warm working. The influence mechanisms of the multi-field coupling on the vacancies diffusion and dislocation movement and rapid crystallization are investigated. Furthermore, the intensity reduction extent of slip-induced equiaxed α phase (0001) texture and the orientation type of stress-induced secondary α phase are determined. In addition, the quantitative relationship between the cooling shrinkage stress of the α phase and the constant stress applied in the coupling is explored. This project not only enhance the understanding of the rapid fine-grained mechanism and the dynamics, but also promote the basic research of α phase orientation selection. It is of significant to optimize preparation technology of medical fine-grain titanium alloy.

英文关键词： multi-field coupling;titanium alloy;crystallization;orientation