Cooling Rate Correlation between Microstructural Phases and Part Dimensions for EBM-Fabricated Parts

EBM 制造零件的微观结构相与零件尺寸之间的冷却速率相关性

• 批准号: 1405526
• 负责人: Ryan Wicker
• 金额: $ 19.81万
• 依托单位: University of Texas at El Paso
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1405526&HistoricalAwards=false
• 关键词: Cooling; Rate; Correlation; between; Microstructural

This award supports fundamental research on the electron beam melting process, an additive manufacturing technology that builds three-dimensional shapes out of powder metals. The layer-by-layer fabrication process promotes distinct microstructural features dependent on cooling rates that are affected by part dimensions, among other factors. Mesh and foam cellular structures are a particular benefit of additive manufacturing and can be used to improve or increase the strength-to-weight ratio of production parts in the aerospace and other industries. Previously, these mesh and foam cellular structures fabricated by electron beam melting using a titanium alloy contained a titanium martensitic brittle phase that, hypothesized in this research, can be avoided by controlling the cooling rates during fabrication. Cooling rates will be measured with a multi-wavelength pyrometer to obtain point-specific, layer-by-layer part temperatures; and the smallest part dimensions that can be fabricated without compromising mechanical properties and microstructural architectures will be determined. Research results and dissemination of these results will provide recommendations and strategies to the broad additive manufacturing and metals fabrication communities to avoid the occurrence of brittle microstructures regardless of part dimensions. The lack of the titanium martensitic brittle phase will allow freedom in the design of parts containing mesh and foam cellular structures without compromising mechanical properties, which will provide an unprecedented benefit for using additive manufacturing technologies to directly fabricate next generation metallic components. The research will be performed at the University of Texas at El Paso, a minority serving institution with a Hispanic-majority student population, providing an unparalleled experience for the students involved in the program in the growing field of additive manufacturing.

该奖项支持电子束熔化工艺的基础研究，这是一种用粉末金属构建三维形状的增材制造技术。层接层的制造工艺促进了不同的微观结构特征，这取决于受零件尺寸影响的冷却速度，以及其他因素。网状和泡沫细胞结构是增材制造的一个特别优势，可用于改善或增加航空航天和其他行业生产部件的强度重量比。在此之前，通过电子束熔化使用钛合金制造的这些网状和泡沫细胞结构含有钛马氏体脆性相，在本研究中假设，可以通过控制制造过程中的冷却速度来避免这种情况。冷却速率将用多波长高温计测量，以获得特定点的逐层部件温度；在不影响机械性能和微观结构的情况下，可以制造的最小零件尺寸将被确定。研究结果和这些结果的传播将为广泛的增材制造和金属制造界提供建议和策略，以避免发生脆性微结构，无论零件尺寸如何。由于缺乏钛马氏体脆性相，因此可以在不影响机械性能的情况下自由设计包含网格和泡沫细胞结构的部件，这将为使用增材制造技术直接制造下一代金属部件提供前所未有的好处。该研究将在德克萨斯大学埃尔帕索分校（University of Texas at El Paso）进行，这是一所以西班牙裔学生为主的少数族裔服务机构，为参与该项目的学生在不断发展的增材制造领域提供无与伦比的体验。