The Synthesis and Characterization of Ultra-Incompressible, Superhard Borides

这项由材料研究部固态材料化学项目授予加州大学洛杉矶分校的奖项是为了生长二硼化Re(ReB2)单晶，并测量作为晶体取向函数的ReB2的物理性质。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，Re将被钛等其他过渡金属完全取代，同时保持ReB2结构类型。这些方法可能使使用更便宜的金属构建新的超不可压缩、超硬材料成为可能。寻找新的超不可压缩、超硬材料既有科学价值，也有实际意义。建议的设计方案是将高价电子密度过渡金属与小主族元素相结合，以强共价键取代弱金属键。使用这种方法，可以将相对较软的Re金属转化为极硬的二硼化Re，它具有许多令人兴奋的物理特性，包括低不可压缩性、高硬度和划痕钻石的能力。涂层的合成和测试将与当地一家专门开发超硬涂层的公司合作进行。硬度、断裂韧性和杨氏S模数将通过压痕技术来确定。径向衍射实验也将被用来确定这些材料的机械性能。作为该项目的一部分，将制定一个名为？IT？S？物质世界？的外联方案。这既适合本科生，也适合普通观众。加州大学洛杉矶分校的本科生每年都会开设这门课程，以提高他们对材料化学的兴趣。此外，为本课程开发的材料将用于与高中生和中学生的互动研讨会。该提议的主要目的是合成二硼化Re晶体和其他结构相关的过渡金属硼化物，如钛。使用这种方法，可以将相对较软的金属转化为比钻石更硬的极硬材料。寻找新的超不可压缩、超硬材料在许多应用中具有科学和实际意义。将制定一个名为？IT？S？物质世界？的外展计划。这既适合在校本科生，也适合普通观众。该课程面向非理科本科生，旨在提高他们对科学，特别是材料科学的兴趣。此外，为本课程开发的材料将用于与高中生和中学生的互动研讨会。

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.