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

该奖项支持电子束熔化工艺的基础研究，这是一种增材制造技术，可以用粉末金属构建三维形状。 逐层制造工艺促进了取决于冷却速率的不同微观结构特征，所述冷却速率受部件尺寸等因素的影响。 网状和泡沫多孔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中生产部件的强度重量比。 以前，这些网格和泡沫蜂窝状结构制造的电子束熔化使用钛合金含有钛马氏体脆性相，在本研究中假设，可以避免在制造过程中控制冷却速率。 冷却速率将使用多波长高温计测量，以获得特定点的逐层零件温度;并确定可以在不影响机械性能和微结构体系结构的情况下制造的最小零件尺寸。 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社区提供建议和策略，以避免发生脆性微观结构，无论零件尺寸如何。 钛马氏体脆性相的缺乏将允许在不损害机械性能的情况下自由设计含有网状和泡沫蜂窝结构的部件，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进行，这是一所少数民族服务机构，学生人口以西班牙裔为主，为参与该计划的学生提供无与伦比的经验。

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.