Collaborative Research: Revealing the Role of Vacancy Order in Regulating the Dislocation Behavior in Transition Metal Carbides

合作研究：揭示空位序在调节过渡金属碳化物位错行为中的作用

• 批准号: 2026760
• 负责人: Gregory Thompson
• 金额: $ 38.05万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2026760&HistoricalAwards=false
• 关键词: Collaborative; Research; Revealing; Role; Vacancy

NON-TECHNICAL DESCRIPTION: Transition metal carbides are a class of ceramics that have a wide range of uses including cutting materials, nuclear energy, and coatings. These applications subject these materials to both temperature and mechanical loads, which they must withstand in service. This project investigates the role of chemistry and crystal structure in controlling the mechanical mechanisms responsible for these properties. Through this project, graduate students will be trained to test, characterize, model and predict the mechanical behavior of transition metal carbides. Those students typically find employment in the energy, defense, and aerospace sectors of society. In addition, this project develops secondary education learning modules that explain hardness, as a technical definition, to middle and high school students.TECHNICAL DETAILS: The transition metal carbides are known to have unique mechanical properties which are intimately linked to their chemistry and structure. This project investigates how this chemistry, and specifically the order of the carbon atoms, controls the mechanical mechanisms responsible for peculiar anomalous hardening and low temperature creep in these carbides. The experimental and computational research develops synergic support in elucidating the fundamental mechanics of dislocations in these ceramics relative to temperature, chemistry, and most importantly, the order of the non-metal sublattice. This project provides, for the first time, a description of the mechanical properties in terms of chemical order using the order parameter. This project is particularly relevant now given the importance of these materials for use in the energy, aerospace, and defense industries, especially the area of applied hypersonics. Furthermore, understanding the mechanistic link for such mechanical properties will aid the development of new compositionally complex transition metal carbides. Given the nature of the research, the graduate students are trained in an integrated manner for the two complementary areas - advanced materials characterization and materials modeling. This research further enhances the field through symposiums led by the investigators on the deformation mechanisms in ceramics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：过渡金属碳化物是一类具有广泛用途的陶瓷，包括切割材料，核能和涂层。这些应用使这些材料承受温度和机械载荷，它们必须在使用中承受这些载荷。该项目研究化学和晶体结构在控制这些性能的机械机制中的作用。通过这个项目，研究生将接受培训，以测试，表征，建模和预测过渡金属碳化物的机械行为。这些学生通常在能源，国防和航空航天领域找到工作。此外，本项目还开发了中等教育学习模块，向初中生和高中生解释硬度的技术定义。技术参数：已知过渡金属碳化物具有独特的机械性能，这些性能与其化学和结构密切相关。该项目研究了这种化学，特别是碳原子的顺序，如何控制这些碳化物中特殊的异常硬化和低温蠕变的机械机制。实验和计算研究开发协同支持阐明这些陶瓷中位错的基本力学相对于温度，化学，最重要的是，非金属亚晶格的顺序。该项目首次使用序参数从化学序的角度描述了力学性能。考虑到这些材料在能源、航空航天和国防工业，特别是应用高超音速领域的重要性，这个项目现在特别重要。此外，了解这种机械性能的机械联系将有助于开发新的组成复杂的过渡金属碳化物。鉴于研究的性质，研究生在两个互补的领域-先进的材料表征和材料建模的综合方式进行培训。这项研究通过由研究人员领导的关于陶瓷变形机制的研讨会进一步加强了该领域。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估而被认为值得支持。

项目成果

Statistical study of vacancy diffusion in TiC and TaC

• DOI: 10.1103/physrevmaterials.4.093602
• 发表时间: 2020-09
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Xiaochuan Tang;Rofiques Salehin;G. Thompson;C. Weinberger

The role of entropy and enthalpy in high entropy carbides

• DOI: 10.1016/j.commatsci.2022.111474
• 发表时间: 2022-07
• 期刊: Computational Materials Science
• 影响因子: 3.3
• 作者: Xiaochuan Tang;G. Thompson;Kaka Ma;C. Weinberger

The effects of mixing non-metal atoms in the B1 structured transition metal carbo-nitrides on their structure and mechanical properties: HfC1-N

• DOI: 10.1016/j.oceram.2023.100356
• 发表时间: 2023-04
• 期刊: Open Ceramics
• 作者: Brennan R. Watkins;Jessica J. Lopez;Xiao-xiang Yu;Gregory B. Thompson;C. Weinberger