基于动力学多元扩散结开发的近β钛合金等温ω相变研究

项目名称： 基于动力学多元扩散结开发的近β钛合金等温ω相变研究

项目编号： No.51301135

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 唐斌

作者单位： 西北工业大学

项目金额： 25万元

中文摘要： 近β钛合金因其具有高淬透性、超高强度以及宽泛的组织性能可调控性，成为高强钛合金的重要发展方向，在航空航天大型结构锻件及高强紧固件上应用广泛。而ω相辅助次生纳米α相形核是近β钛合金重要的强化机制，但是，对于多组元近β钛合金，由于多元素对等温ω相变的耦合作用机制尚不明确，严重制约了微观组织控制技术的发展以及新型合金的开发。本项目通过发展动力学多元扩散结技术，结合"高空间分辨率"测试手段，系统研究合金元素在β基体中的扩散路径及其耦合作用对等温ω相变机制的影响，并建立复合动力学数据库。基于该数据平台，发展描述近β钛合金中等温ω相变过程的定量相场模型，研究成分场、弹性力场以及界面能的耦合作用对ω相形貌演化、尺寸及分布规律的影响，揭示合金成分与热处理工艺对等温ω相变动力学的影响规律，为发展近β钛合金的组织控制技术奠定基础。

中文关键词： 钛合金；相变；相场法；扩散连接；

英文摘要： Near β Ti alloys are finding widespread application particularly in aerospace as large structural forging components thanks to their advantages of deeper hardenability, super high strength, and adjustable microstructure and mechanical properties, thus becoming an important development direction of high strength Ti alloys. The presence of the ω phase was found to provide the preferential nucleation sites that triggers the formation of the secondary nano-size α phase and subsequently improve the strength of near β Ti alloys. However, the coupling influence of elements on isothermal ω phase transformation in engineering near β Ti alloys is still not well understood largely due to the complexity arising from multicomponent alloying elements. Therefore, the developing of microstructure controlling technique and the designing of new alloys are seriously limited. In this project, the coupling influence of elements on diffusion pathway and isothermal ω phase transformation in engineering near β Ti alloys is systematically investigated based on the development of kinetic Diffusion Multiple (DM) technique and the application of "high-spatial-resolution" microanalysis methods. In addition, the DM will ultimately enable kinetic information to be extracted and composition-kinetics libraries to be generated in a combinatoria

英文关键词： titanium alloy；phase transformation；phase field method；diffusion bonding；