The Determination of Activation Energies and Modeling of Low Temperature (<0.25Tm) Creep Behavior of Alpha, Alpha-Beta and Beta Titanium Alloys

技术支持：钛合金正在寻找低温（0.25Tm）应用，例如用于核废料储存的防滴板，其中蠕变行为可以发挥重要作用。为了在这些应用中有效地使用钛合金并设计新的合金，需要更好地理解变形机制和微观结构之间的关系。该小组过去的研究重点包括确定β钛合金蠕变的激活能，开发随时间变化的孪晶的晶体学模型，以及确定两相钛合金新变形机制的透射和高分辨率电子显微镜研究。尚未解决的问题包括如何时间依赖孪生发生在？α-β钛合金中出现新的变形机制的原因以及变形机制与形貌的关系。解决这些问题是本次调查的主题。调查包括三维，各向异性有限元建模，以确定α和β相之间的相互作用。这项研究的输出是建模，结合变形机制，微观结构和晶体结构的钛。非技术性：虽然模型系统是钛合金，但研究结果应该适用于其他合金系统，特别是锆合金系统。这项调查涉及研究生和本科生，学生将学习实验技能，如机械测试，透射和高分辨率电子显微镜，以及数据分析和技术报告写作技能。此外，将尽一切努力招收少数民族学生。高级研究员是TMS/ASM学生分会的创始教师顾问;过去四年，该分会获得了“卓越章”奖。本章参加全国专业协会会议，教育高中学生谁来开放的房子在大学，和部门的教育活动。

TECHNICAL: Titanium alloys are finding low temperature (0.25Tm) applications, such as in drip shields for nuclear waste storage where creep behavior can play an important role. For effective use of titanium alloys in these applications and to design new alloys, the relationships between deformation mechanisms and microstructures need to be better understood. Past research highlights by this group include determination of the activation energy for creep of beta titanium alloys, development of crystallographic models for time-dependent twinning, and transmission and high-resolution electron microscopy studies that identify new deformation mechanisms in two-phase titanium alloys. Unresolved issues include how time-dependent twinning occurs in ?alpha titanium alloys, why new deformation mechanisms occur in alpha-beta titanium alloys and the relation between morphology and deformation mechanisms. Addressing these issues is the subject of this investigation. The investigation includes 3-dimensional, anisotropic finite element modeling to determine the interaction between alpha and beta phases. An output of this investigation is modeling that incorporates deformation mechanisms, microstructure, and crystal structure in titanium. NONTECHNICAL: Although the model systems are titanium alloys, the research results should be applicable to other alloy systems, in particular those of zirconium. This investigation involves both graduate and undergraduate students and the students will learn experimental skills such as mechanical testing, transmission and high-resolution electron microscopy, as well as data analysis and technical report writing skills. In addition, every attempt will be made to recruit minority students. The senior researcher is the founding faculty advisor for the TMS/ASM student chapter; the last four years the chapter received the "Chapter of Excellence" award. This chapter participates in national professional society meetings, educating high school students who come to open houses at the university, and the departmental educational activities.