TiNb系亚稳β钛合金α及ω相变的表面效应研究

项目名称： TiNb系亚稳β钛合金α及ω相变的表面效应研究

项目编号： No.51471017

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： 赵新青

作者单位： 北京航空航天大学

项目金额： 85万元

中文摘要： 鉴于α马氏体和ω相对亚稳β钛合金功能特性及力学性能的重要作用，α及ω相的形成、演化及其与力学行为的关系一直是先进钛合金和固体物理领域的关键科学问题。我们近期的实验研究表明，亚稳β钛合金的α马氏体相变及ω相变具有显著的表面效应，α马氏体相变只发生在合金表层而非内部，同时α相形成与ω相析出具有高度相关性。阐明该表面效应的物理机制以及α相变与ω相变的相关性，将深化亚稳β钛合金中的固态相变学术研究。本项目拟以TiNb系亚稳β钛合金为对象，深入研究合金的结构稳定性、冷却速率和表面应力等因素对α及ω相变表面效应的影响规律，阐明表面效应的物理机制以及α相变与ω相变的相关性；利用α马氏体相变的表面效应，制备具有不同稳定性的单一β相亚稳β钛合金，分析表征结构稳定性与力学行为的关系，揭示应力诱发α马氏体相变与合金力学行为的相互作用机制，为新型亚稳β钛合金的设计和研发提供技术支持。

中文关键词： 亚稳β钛合金；相变；表面效应；力学行为；TiNb系

英文摘要： Because of the importance of α martensite and ω phase for the functional performance and mechanical properties of metastable β titanium alloys, the formation and their evoluation of α and ω phases as well the relationship between their transformation and the mechanical behavior have been key issues in the fields of advanced titanium alloys and in solid physics. It was found in recent experimental study that during the quenching of metastable β titanium alloys，substancial surface effect of α martensitic transformation and ω precipitation occurred，i.e. α martensitic transformation only take place on the surface and a close correlation exists between the formation of α and ω phases. It is of academic significance and technical importance to clarify the mechanism for the surface effect of α martensitic transformation and correlation between the formation of α and ω phases, which will deepen the study of martensitic transformation in metastable β Ti alloys. The aim of the present study is to clarify the influence of the structural stability, cooling rate and surface stress on the surface effect of α and ω phase transformation, and to determine the physical mechanism of surface effect and the relationship between α and ω phase transformation. In addition, single β phase Ti alloys with different strcutual stability will be prepared and the relationship between structual stability and deformation behavior will be investigated, in attempt to discover the origin for the relation of martensitic transformation and mechanical behavior, laying a basis for the design and development of advanced metastable β Ti alloys.

英文关键词： metastable β-Ti alloys;phase transformation;surface effect;mechanical behavior;TiNb based