The Synthesis and Characterization of Ultra-Incompressible, Superhard Borides

超不可压缩、超硬硼化物的合成和表征

• 批准号: 0805357
• 负责人: Richard Kaner
• 金额: $ 67.5万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-10-01 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0805357&HistoricalAwards=false
• 关键词: Synthesis; Characterization; Ultra; Incompressible; Superhard

This award to University of California-Los Angeles by the Solid State Materials Chemistry program in the Division of Materials Research is to grow single crystals of Rhenium diboride (ReB2) and to measure the physical properties of ReB2 as a function of crystallographic orientation. The hardness of ReB2 will then be enhanced by forming solid solutions and synthesizing dense nanocrystalline composites. In other studies, rhenium will be replaced completely with other transition metals such as Titanium while maintaining the ReB2 structure type. These approaches may enable to construct new ultra-incompressible, superhard materials using less expensive metals. The search for new ultra-incompressible, superhard materials holds both scientific and practical interest. The proposed design plan is to combine high valence electron density transition metals with small main group elements to replace the weak metallic bonds with strong covalent bonds. Using this approach, it is possible to convert relatively soft rhenium metal into an extremely hard Rhenium diboride, which has many exciting physical properties including low incompressibility, high hardness, and the ability to scratch diamond. Synthesis and testing of coatings will be carried out in conjunction with a local company that specializes in developing ultra-hard coatings. Hardness, fracture toughness and Young?s modulus will be determined by indentation techniques. Radial diffraction experiments will also be used to determine the mechanical properties of these materials. As part of this project, an outreach program be developed entitled ?It?s a Material World? that is suitable for both undergraduate students and general audiences. This course will be offered to UCLA undergraduates each year to enhance their interest in materials chemistry. In addition, materials developed for this course will be used for interactive seminars with both high school and middle school students. The main thrust of the proposal is to synthesize crystals of Rhenium Diboride and other structurally related borides of transition metals such as Titanium. Using this approach, it is possible to convert relatively soft metals into extremely hard materials, which are harder than diamond. The search for new ultra-incompressible, superhard materials holds both scientific and practical interest in a number of applications. An outreach program will be developed entitled ?It?s a Material World? that is suitable for both undergraduate students at the campus and general audiences. This program offered to non-science undergraduate students is to enhance their interest in science in general and materials science in particular. In addition, materials developed for this course will be used for interactive seminars with both high school and middle school students.

加州大学洛杉矶分校材料研究部固态材料化学项目的这一奖项是为了生长二硼化铼（ReB2）单晶，并测量ReB2的物理性质作为晶体取向的函数。 然后通过形成固溶体和合成致密的纳米晶复合材料来提高ReB2的硬度。 在其他研究中，ReB2将被其他过渡金属（如钛）完全取代，同时保持ReB2结构类型。这些方法可以使用较便宜的金属来构造新的超不可压缩的超硬材料。寻找新的超不可压缩的超硬材料具有科学和实际意义。 提出的设计方案是将高价电子密度的过渡金属与小主族元素结合，用强共价键取代弱金属键。使用这种方法，可以将相对较软的金属转化为极硬的二硼化铼，其具有许多令人兴奋的物理特性，包括低不可压缩性，高硬度和刮擦金刚石的能力。 涂料的合成和测试将与当地一家专门开发超硬涂料的公司合作进行。硬度、断裂韧性和杨氏？S模量将通过压痕技术来确定。径向衍射实验也将用于确定这些材料的机械性能。 作为该项目的一部分，将制定一项名为？是吗？这是一个物质世界？适合本科生和普通观众。本课程将每年提供给加州大学洛杉矶分校的本科生，以提高他们对材料化学的兴趣。此外，为这门课程开发的材料将用于与高中和初中学生的互动研讨会。该提案的主要目的是合成二硼化铼和其他结构相关的过渡金属硼化物（如钛）的晶体。 使用这种方法，可以将相对较软的金属转化为比金刚石更硬的极硬材料。 寻找新的超不可压缩的超硬材料在许多应用中具有科学和实际意义。将制定一项外联方案，题为？是吗？这是一个物质世界？既适合校园里的本科生，也适合一般观众。该计划提供给非科学本科生是为了提高他们对科学的兴趣，特别是材料科学。此外，为这门课程开发的材料将用于与高中和初中学生的互动研讨会。