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

活化能的测定和低温建模（

• 批准号: 0513751
• 负责人: Sreeramamurthy Ankem
• 金额: --
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0513751&HistoricalAwards=false
• 关键词: Determination; Activation; Energies; Modeling; Low

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.

技术：钛合金正在发现低温（0.25tm）的应用，例如在滴水罩中用于核废物储存的盾牌，蠕变行为可以发挥重要作用。为了在这些应用中有效使用钛合金并设计新合金，需要更好地理解变形机制和微观结构之间的关系。该组的过去研究重点包括确定β钛合金蠕变的活化能，开发用于时间依赖的双胞胎的晶体学模型，以及传播和高分辨率电子显微镜研究，这些研究鉴定了两相钛合金中的新变形机制。尚未解决的问题包括α钛合金中如何发生时间依赖性的双胞胎，为什么在α-beta钛合金中发生新的变形机制以及形态和变形机制之间的关系。解决这些问题是这项调查的主题。该研究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，该建模结合了钛中的变形机制，微结构和晶体结构。非技术性：尽管模型系统是钛合金，但研究结果应适用于其他合金系统，尤其是锆石的系统。这项调查涉及研究生和本科生，学生将学习实验技能，例如机械测试，传输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，将每次尝试招募少数民族学生。高级研究员是TMS/ASM学生分会的创始教师顾问；在过去的四年中，本章获得了“卓越分会”奖。本章参加了国家专业协会会议，对来大学开放式房屋的高中学生以及部门的教育活动进行教育。