Shear Strength and Phase Transformations in Transition Metals and their Diborides under Terapascal Pressures

兆帕压力下过渡金属及其二硼化物的剪切强度和相变

• 批准号: 1904164
• 负责人: Yogesh Vohra
• 金额: $ 38.26万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904164&HistoricalAwards=false
• 关键词: Shear; Strength; Phase; Transformations; Transition

PART 1: NON-TECHNICALThe transition metals (such as iron, manganese, copper and lesser known elements rhenium and osmium) and their alloys are widely used in aerospace, biomedical, and nuclear industries while transition metal diborides (one atom transition metal and 2 atoms of boron) have potential applications as high-strength structural materials under extreme conditions of stress, temperature, and corrosive environments. The application of high pressure on transition metals and their diborides is expected to yield novel structural modifications with desirable mechanical properties. The phase transformation studies and shear strength measurements on materials under high-pressures will be carried out using an innovative diamond anvil technology coupled to an x-ray synchrotron source. The computational calculations will use the state-of-the-art supercomputing facilities to predict stable crystal structures and their elastic properties and shear strength. This study will map out the crystalline phases and their shear strength with varying pressure with a goal of novel material synthesis that can be retained at ambient conditions for industrial applications. The project participants will receive extensive research and curriculum training in computational materials research and at the premier national facilities employing x-ray synchrotron radiation leading to a pipeline of trained scientific workforce in academia, national laboratories and industry. University of Alabama at Birmingham in partnership with the Historically Black Colleges and Universities in the southeastern region will jointly undertake efforts in broadening participation of underrepresented groups at all levels in the science and engineering fields.PART 2: TECHNICAL The study of phase transformations and shear strength measurements under high-pressures not only provides key-insights into mechanical properties under pressure but also provides a pathway to synthesizing novel materials under extreme conditions. The study of materials under extreme conditions has seen rapid progress recently with the attainment of near Terapascal (1 TPa = 1000 GPa) static pressures using toroidal single crystal diamond anvils and by employing two-stage nanocrystalline diamond micro-anvils. In addition, density functional theory has been applied to compute stable crystal structures and their elastic constants at high pressure for direct comparison with the experimental data on elastic moduli and shear strength under ultrahigh pressures. University of Alabama at Birmingham will perform phase transformations and shear strength measurements on rhenium (Re), osmium (Os), and their diborides ReB2 and OsB2 under both hydrostatic (helium pressure medium) and non-hydrostatic (no pressure medium) conditions. The ReB2 and OsB2 have high hardness values at ambient conditions in the range of 22-37 GPa and their shear strength variation with pressure is of considerable interest. The TPa pressure range is expected to cause significant electron transfer within the conduction band and possibly cause core-overlap leading to novel structural modifications with desirable mechanical properties. This study would provide crystal structure data and shear strength data for this unique electronic state of transition metals and their diborides under extreme conditions for direct comparison with the density functional calculations.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.

第 1 部分：非技术过渡金属（如铁、锰、铜和鲜为人知的元素铼和锇）及其合金广泛应用于航空航天、生物医学和核工业，而过渡金属二硼化物（一个过渡金属原子和两个硼原子）在应力、温度和腐蚀环境的极端条件下具有作为高强度结构材料的潜在应用。对过渡金属及其二硼化物施加高压有望产生具有理想机械性能的新型结构修饰。高压下材料的相变研究和剪切强度测量将使用与 X 射线同步加速器源耦合的创新金刚石砧技术进行。计算计算将使用最先进的超级计算设施来预测稳定的晶体结构及其弹性特性和剪切强度。这项研究将绘制不同压力下的晶相及其剪切强度，目标是合成可在工业应用的环境条件下保留的新型材料。项目参与者将在计算材料研究方面接受广泛的研究和课程培训，并在采用 X 射线同步加速器辐射的主要国家设施中接受培训，为学术界、国家实验室和工业界培养一批训练有素的科学劳动力。阿拉巴马大学伯明翰分校将与东南部地区的历史悠久的黑人学院和大学合作，共同努力扩大科学和工程领域各级代表性不足群体的参与。第二部分：技术高压下相变和剪切强度测量的研究不仅提供了压力下机械性能的关键见解，而且还提供了在极端条件下合成新型材料的途径。极端条件下的材料研究最近取得了快速进展，使用环形单晶金刚石砧和两级纳米晶金刚石微砧实现了近兆帕斯卡（1 TPa = 1000 GPa）的静压。此外，密度泛函理论还用于计算高压下稳定的晶体结构及其弹性常数，以便与超高压下弹性模量和剪切强度的实验数据直接进行比较。阿拉巴马大学伯明翰分校将在静水（氦压力介质）和非静水（无压力介质）条件下对铼 (Re)、锇 (Os) 及其二硼化物 ReB2 和 OsB2 进行相变和剪切强度测量。 ReB2 和 OsB2 在环境条件下具有 22-37 GPa 范围内的高硬度值，并且它们的剪切强度随压力的变化非常令人感兴趣。 TPa 压力范围预计会在导带内引起显着的电子转移，并可能导致核心重叠，从而导致具有所需机械性能的新颖结构修改。这项研究将为过渡金属及其二硼化物在极端条件下的这种独特电子态提供晶体结构数据和剪切强度数据，以便与密度泛函计算直接比较。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Experimental and theoretical P-V-T equation of state for Os 2 B 3

Os 2 B 3 的实验和理论 P-V-T 状态方程

• DOI: 10.1080/08957959.2020.1858821
• 发表时间: 2020
• 期刊: High Pressure Research
• 影响因子: 2
• 作者: Burrage, Kaleb C.;Lin, Chia-Min;Chen, Wei-Chih;Chen, Cheng-Chien;Vohra, Yogesh K.
• 通讯作者: Vohra, Yogesh K.

Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures

• DOI: 10.3390/ma13071657
• 发表时间: 2020-04-01
• 期刊: MATERIALS
• 影响因子: 3.4
• 作者: Burrage, Kaleb C.;Lin, Chia-Min;Vohra, Yogesh K.
• 通讯作者: Vohra, Yogesh K.

Theoretical and experimental studies of compression and shear deformation behavior of Osmium to 280 GPa

280 GPa 锇压缩和剪切变形行为的理论和实验研究

• DOI: 10.1088/2631-8695/ac34c4
• 发表时间: 2021
• 期刊: Engineering Research Express
• 影响因子: 1.7
• 作者: Lin, Chia Min;Burrage, Kaleb C;Perreault, Chris;Chen, Wei-Chih;Chen, Cheng-Chien;Vohra, Yogesh K
• 通讯作者: Vohra, Yogesh K

Shear strength measurements and hydrostatic compression of rhenium diboride under high pressures

• DOI: 10.1063/5.0050057
• 发表时间: 2021-05-28
• 期刊: JOURNAL OF APPLIED PHYSICS
• 影响因子: 3.2
• 作者: Burrage, Kaleb C.;Park, Changyong;Vohra, Yogesh K.
• 通讯作者: Vohra, Yogesh K.