Near-net Shape Processing of Functionally Graded Structural Material

本研究的目的是通过数学和物理模拟来优化一种精确控制性能的多孔结构材料的近净成形生产方法。压力辅助燃烧合成法(PACS)将传统的自蔓延高温合成和发泡技术结合在一起。研究方法由理论和实验两部分组成。建立了该工艺的多尺度数学模型，以量化组织-性能关系，并建立了生产所需组织的参数空间。然后，利用从数学模型中获得的工艺条件，将PAC用于合成多孔金属间化合物材料。对所生产的材料进行显微镜和机械测试，结果用于验证数学模型，找出缺陷并优化工艺。交付内容包括跨维度尺度的建模和分析工具、学生教育以及将研究结果记录在报告、期刊和论文中。如果这项研究成功，将提供一种具有成本效益、能源效率和环境友好的方法来生产具有所需微观结构和力学性能的多孔结构材料。应用实例包括优化网状生物医学结构植入物的生产，以改善假体程序的结果，降低成本，降低失败率，并提高假体患者的生活质量。该方法也适用于更广泛的涉及具有运动界面的非线性耦合输运-反应现象的复杂材料过程。许多这样的工艺与国防和商业对材料的关键需求有关，例如用于高速民用运输燃烧室的近净形状整体陶瓷或陶瓷复合材料。本科生和研究生将从事这项研究，并将受益于课堂教学和材料加工、反应工程、热学和数值方法等不同领域的多学科培训。

The objective of this research is to optimize through mathematical and physical modeling, a method for near-net shape production of porous structural materials with accurately controlled properties. The method, pressure-assisted combustion synthesis (PACS), combines conventional self-propagating high-temperature synthesis and foaming in one operation. The research approach has theoretical and experimental components. A multi-scale mathematical model of the process is developed to quantify the microstructure-property relationship and establish the parameter space for production of the desired microstructure. PACS is then used to synthesize porous intermetallic material, utilizing the processing conditions obtained from the mathematical model. The materials produced are subjected to microscopy and mechanical testing, and the results are used to validate the mathematical model, identify deficiencies and optimize the process. Deliverables include modeling and analysis tools across dimensional scales, student education, and documentation of research results in reports, journals, and theses. This research, if successful, will provide a cost-effective, energy efficient and environmentally benign method for producing porous structural materials with desired microstructure and mechanical properties. Example application includes optimization of the production of net-shape biomedical structural implants to improve the outcomes of prostheses procedures, reduce costs, reduce failure rates, and enhance the quality of life of patients with prostheses. The methodology is also applicable to a wider class of complex materials processes involving non-linear coupled transport-reaction phenomena with moving interfaces. Many such processes are relevant to critical defense and commercial needs for materials such as near-net shape monolithic ceramics or ceramic composites for the High Speed Civil Transport combustors. Undergraduate and graduate students will be engaged in the research, and will benefit from classroom instruction and the multidisciplinary training in diverse fields of materials processing, reactive engineering, thermal science and numerical methods.