Effect of Alloying and Thermo-Mechanical-Treatment on Anisotropic Creep and Deformation of Ti-alloys

研究了热机械处理(TMT)和合金化对钛合金形变和蠕变各向异性的影响。这项研究涉及钛合金的各向异性双轴蠕变特性的研究，使用封闭式内压薄壁管材叠加轴向载荷。方法是研究在去应力退火热处理和完全再结晶后的Ti和Ti-3Al-2.5V中的这些行为。添加Al和Ti等合金化元素会显著改变合金的晶体织构和滑移系。冷加工导致Rx材料等轴晶组织的晶形各向异性。这些变量对变形组织的影响以及在不同应力状态和应力水平下双轴加载后的变形各向异性被研究。蠕变机制的转变和潜在变形机制(S)对蠕变各向异性的影响也将被讨论。这些研究对于真实估计这些结构材料在使用中的蠕变应变和寿命很重要。%该项目解决了当代材料科学的一个热门领域的基础研究问题，该领域与航空航天、汽车和化工部门的技术相关，其中钛合金以管状形式使用。该计划的一个重要特点是通过在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。该项目预计将为研究生和本科生提供独特的机会，通过在前沿研究环境中的经验发展强大的技术、沟通和组织/管理技能。***

This project addresses the influence of thermo-mechanical-treatment (TMT) and alloying on deformation and creep anisotropy of titanium alloys. The research involves characterization of anisotropic biaxial creep of Ti alloys using closed-end internally pressurized thin-walled tubing superimposed with an axial load. The approach is to investigate these behaviors in Ti and Ti- 3Al-2.5V following stress-relief anneal and complete recrystallization. Alloying additions such as Al to Ti result in significant modification of crystallographic texture and operating slip systems. Cold-working leads to grain-shape anisotropy of the otherwise equiaxed grain structure of Rx materials. The effects of these variables on deformation microstructures are to be investigated along with deformation anisotropy following biaxial loading under varied stress-states and stress-levels. Transitions in creep mechanisms and the effect of underlying deformation mechanism(s) on creep anisotropy will also be addressed. Such studies are important for realistic estimates of creep strains and life of these structural materials in service.%%% The project addresses basic research issues in a contemporary topical area of materials science with technological relevance in aerospace, automobile, and chemical sectors where Ti-alloys are used in tube form. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The project is expected to provide unique opportunities for graduate and undergraduate students to develop strong technical, communication, and organizational/management skills through experiences in a forefront research environment. ***