SGER: Investigation of a Combinatorial Mechanical Alloying-Activated Sintering (MA-AS) Technique for the Synthesis of Age-Hardenable, Self-lubricating Bearings by Powder Metallurgy

SGER奖支持通过粉末冶金合成时效硬化铝合金的组合材料加工技术的研究，这种技术也可以通过分散细小的氧化物相来同时强化。众所周知，铝粉表面存在一层坚韧的氧化膜，阻碍了粉末压坯的压制和烧结，阻碍了铝粉的烧结。众所周知，在合金基质中分散难熔氧化物颗粒可提高硬度和强度；然而，如果不使用复杂的方法，技术上的困难很难克服。已知机械合金化技术对于诱导材料的固态扩散和合金化具有显著的益处。采用等离子活化法和类似技术相结合的烧结工艺，可合成难熔金属、金属间化合物、金属玻璃和其他难熔材料。本文研究了机械合金化和化学活化烧结Al-Cu时效硬化合金的新组合。在本工作中，铝粉将与片状或片状的纳米铜粉机械合金化，并通过暴露于选定的稀有机酸进行化学活化，以在处理后的粉末上提供合适的金属-有机表面膜。这些薄膜在低温下的分解将为合金粉末的快速烧结和致密化提供高度活性的表面。将对烧结体进行热处理，以提供时效硬化效果。同时，氧化铝颗粒在机械合金化过程中的弥散将为烧结合金的弥散强化提供可能性。该项目将为有进取心的年轻工科学生提供独特和极好的机会，让他们在先进材料和制造技术方面进行前沿研究，并了解纳米结构和工程材料的潜在好处。这一研究计划的建立将为PI提供一个独特的机会，以开发新的和令人兴奋的课堂和实验室教学材料和课程，以加强研究工作。PI正在参与由阿肯色大学管理的乔治·华盛顿·卡弗项目，该项目为来自阿肯色州历史上黑人学院和大学(HBCU)的有前途和有才华的年轻本科生提供机会，体验科学或工程职业生涯的兴奋和好处。根据这项计划，被选中的年轻人将在校园里呆上几个星期，与一名教职员工一起工作，并协助正在进行的或特别开发的研究项目。在即将到来的暑期课程中，PI将在卡弗项目下支持一名本科生。学生将在这个SGER项目中工作，帮助一名机械工程研究生建立和使用实验室的粉末冶金加工设备，并进行实验室实验。学生将学习研究方法、实验室程序和安全问题、研究文件和实验数据分析，并在先进材料和制造技术的开发中应用科学和工程原理方面获得实践经验。

This SGER award supports an investigation of combinatorial materials processing techniques for the synthesis of age-hardenable aluminum alloys by powder metallurgy, which can also be simultaneously strengthened by a dispersion of a finely divided oxide phase. It is well known that the sintering of aluminum powder is hampered by the presence of a tenacious oxide film on the surface, which interferes with pressing and sintering of the powder compacts. Beneficial effects of a dispersion of refractory oxide particles in an alloy matrix for enhanced hardness and strength are well known; however, the technical difficulties are not easily overcome without the use of complex methods. Mechanical alloying techniques have been known to provide a significant benefit for inducing solid-state diffusion and alloying of materials. Sintering processes, enhanced by methods of plasma activation and similar techniques, have been used in combination with mechanical alloying to synthesize refractory metals, intermetallics, metallic glasses and other difficult materials.This proposal deals with the study of a novel combination of mechanical alloying and chemically activated sintering of Al-Cu age-hardenable alloys. In this work, powders of aluminum will be mechanically alloyed with nanocrystalline powders of copper of platelet or flake morphology, and subjected to chemical activation by exposure to selected dilute organic acids, to provide suitable metal-organic surface films on the treated powders. The decomposition of these films at low temperatures will provide a highly activated surface for rapid sintering and densification of the alloyed powders. The sintered compacts will be heat treated to provide the age-hardening effect. At the same time, the dispersion of the aluminum oxide particles during mechanical alloying will provide the possibility of dispersion-strengthening of the sintered alloy.This project will provide unique and excellent opportunities to enterprising young engineering students to pursue cutting edge research in advanced materials and manufacturing techniques, and to learn about the potential benefits of nanostructured and engineered materials. The establishment of this research program will provide a unique opportunity for the PI to develop new and exciting classroom and laboratory instructional materials and courses to augment the research effort. The PI is participating in the George Washington Carver Project administered by the University of Arkansas, which provides promising and talented young undergraduate students from the historically black colleges and universities (HBCU) in the State of Arkansas an opportunity to experience the excitement and benefits of a science or engineering career. Under this program, selected youngsters will spend several weeks on campus, working with a faculty member and assisting in an on-going or specially developed research project. The PI will be supporting one undergraduate student under the Carver Project during the upcoming summer session. The student will work on this SGER project, assisting a graduate student in Mechanical Engineering, to set up and use the laboratory P/M processing equipment and conduct laboratory experiments. The student will learn research methods, laboratory procedures and safety issues, research documentation and analysis of experimental data, and acquire hands-on experience in the application of scientific and engineering principles in the development of advanced materials and manufacturing techniques.