Mechanical Behavior of Nanolayered Metal/Ceramic Composite Coatings

技术：这一行动支持一项合作研究计划，以解决多层纳米尺度复合材料的力学行为方面的重要问题。近年来，在纳米尺度上设计的层状材料在产生极高的强度、耐疲劳性、耐热性、耐磨性和生物兼容性方面显示出令人兴奋的可能性。研究计划包括以下主要内容：(I)多层铝/碳化硅复合材料(亚利桑那州)的物理气相沉积(PVD)工艺和微观结构表征(扫描电子显微镜、透射电子显微镜和高分辨电子显微镜)；(Ii)用X射线衍射和中子衍射表征残余应力(橡树岭国家实验室)；(Iii)通过纳米压痕和微力拉伸和疲劳试验(亚利桑那州)；(Iv)用连续介质、位错动力学和原子方法模拟变形行为。通过沉积、表征和小规模力学性能测试等实验手段，研究了金属/陶瓷纳米层的制备工艺、纳米结构与力学性能之间的关系。跨多个长度尺度的计算模拟为纳米层状复合材料的变形和断裂机制提供了基本的见解。非技术性：加强材料教育和公众对纳米层状材料研究的重要性及其在满足社会需求方面的作用的认识是该计划的一个重要组成部分。多样化的教育和外展计划与研究计划相结合，旨在传播、教育和参与各级学生以及公众。该计划加强了亚利桑那州立大学和新墨西哥州大学之间的大学伙伴关系。推广方案包括以下部分：(I)在亚利桑那州立大学和UNM联合开设一门新的纳米材料力学课程；(Ii)在亚利桑那州立大学、UNM和ORNL为本科生开展以项目为基础的活动和研究机会；(Iii)通过亚利桑那州立大学和UNM的外联方案招募和参与代表性不足的女性和少数群体；(Iv)为研究生提供虚拟论文答辩，并创建虚拟研讨会系列；(V)通过创建纳米材料网站提高公众认识。北卡罗来纳大学是一所少数族裔院校，也是一所西班牙裔服务院校，招收近50%的少数族裔学生。亚利桑那州立大学和新墨西哥州州立大学已经建立了现有机制，招募人数不足的女学生和少数族裔学生，并让他们参与进来。合作计划包括：亚利桑那州立大学的学生外展和保留计划(SORP)、美国国家航空航天局(NASA)在新墨西哥州州立大学(UNM)的大学本科生研究准备计划(NASA Process)、该大学多元文化工程计划中的“研究生桥梁计划”(Graduate Bridge Program)、以及美国国家航空航天局(NASA)在该大学的夏普(Sharp)高中学徒研究计划。

TECHNICAL: This action supports a collaborative research program to address important issues on the mechanical behavior of multilayered nanoscaled composites. In recent years, layered materials engineered at the nanoscale have exhibited exciting possibilities for producing extremely high strength, fatigue resistance, thermal resistance, wear resistance, and biocompatibility. The research plan consists of following major thrusts: (i) processing by physical vapor deposition (PVD) and microstructure characterization (SEM, TEM, and HRTEM) of multilayered Al/SiC composites (Arizona State); (ii) residual stress characterization by x-ray diffraction and neutron diffraction (Oak Ridge National Laboratory); (iii) deformation behavior by nanoindentation and microforce tensile and fatigue testing (Arizona State); and (iv) simulation of deformation behavior by continuum, dislocation dynamics, and atomistic methodologies. The relationship between processing, nanoscale structure and mechanical properties of metal/ceramic nanolayers is examined by way of experiments employing deposition, characterization and small-scale mechanical testing techniques. Computational simulations across multiple length scales provide fundamental insights into the deformation and fracture mechanisms of nanolayered composites. NONTECHNICAL: Enhancing materials education and public awareness of the importance of nanolayered materials research and its role in addressing societal needs forms a crucial component of the program. A diverse educational and outreach program is integrated with the research program and serves to disseminate, educate, and involve students at all levels as well as the public. The program enhances the university partnership between ASU and UNM. The outreach program has the following components: (i) Creation of a new course on mechanics of nanomaterials offered jointly at ASU and UNM; (ii) Project-based activities and research opportunities for undergraduate students at ASU, UNM, and ORNL; (iii) Recruitment and involvement of underrepresented females and minorities through outreach programs at both ASU and UNM; (iv) virtual thesis defenses for graduate students and the creation of a virtual seminar series; and (v) public awareness by the creation of a website on nanomaterials. UNM is a Minority Institution and a Hispanic Serving Institution with an enrollment of nearly 50% minority students. Existing mechanisms are already in place at ASU and UNM to recruit and involve underrepresented female and minority students. The partnering programs include: Student Outreach and Retention Program (SORP) at ASU, NASA PURSUE (Preparation for University Research of Students in Undergraduate Education) at UNM, the "Graduate Bridge Program" in the Multicultural Engineering Program at UNM, and the NASA SHARP (Summer High-School Apprenticeship Research Program) at UNM.