GOALI: Optical Properties and Visual Appearance of Naturally Oxidized and Anodized Aluminum Surfaces

非技术描述：该提案的重点是与氧化铝合金表面的光学特性和视觉外观相关的广泛的科学问题。铝合金产品(轧制、挤压)的外观外观是铝工业的一个重要问题--超过一半的客户退货不是因为制造的产品的机械和物理性能不佳，而是因为产品表面质量令人无法接受。这种合作要解决的问题对铝行业来说是通用的，但开发对相关工艺的基本原子尺度科学理解的努力超出了单个公司的能力范围。结果将以一种专注于产品开发的行业研究人员可以使用的形式进行预测。该团队包括来自大学(范德比尔特大学和阿拉巴马农工大学)、工业界(美国铝业公司)和橡树岭国家实验室(ORNL)的合作伙伴。俄罗斯科学院的其他合作者也将参与其中。这一新知识将为铝行业控制其生产工艺，实现客户指定的铝产品的理想光学性能提供有价值的指导。这些新知识也将被高中教师纳入适合高中和公众的模块中，他们将在范德比尔特科学外展中心的协调下，在范德比尔特度过几个暑期课程。从事研究的学生，包括阿拉巴马农工大学(一所历史上的黑人大学)的少数族裔学生，将参观并在国家实验室(ORNL)和工业环境(美国铝业技术中心)工作。技术细节：表面的视觉外观和整体质量(亮度、图像的清晰度、彩虹和着色)是一个多尺度问题，将表面和亚表面区域的原子级结构和化学成分以及介观尺度的表面粗糙度与宏观光学性质联系起来。虽然粗糙表面的光散射现象光学已经很发达，但影响特定表面的光学性质和视觉外观的原子、纳米和微米尺度的机制以及表面氧化物、掺杂和缺陷的作用仍然是开放的。一个跨学科团队将使用实验和理论相结合的多尺度方法来系统地解开这些问题，并为处理一个代价高昂的工业问题提供科学依据。这个问题将使用实验和理论工具的广泛组合来解决，例如原子分辨率Z对比透射式电子显微镜、EXAFS、原子力显微镜(AFM)、扫描近场光学显微镜(SNOM)和激光诱导击穿光谱(LIBS)，并辅之以第一性原理理论和计算机模拟。不同长度尺度的实验和理论之间的持续反馈，以及美国铝业科学家提供的丰富的现象学信息数据库，将致力于多尺度、与行业相关的基础研究的前沿示范。这项拟议的研究为研究生和博士后助理提供了独特的机会。他们将接触到作为工业关注基础的“基础科学”研究，同时参与与美国铝业技术中心和ORNL的研究人员的联合工作。在ORNL接受显微镜培训的学生将有机会使用世界上最高分辨率的电子显微镜。

NON-TECHNICAL DESCRIPTION: The focus of the proposal is upon a wide range of scientific issues related to optical properties and visual appearance of oxidized aluminum alloy surfaces. The visual appearance of aluminum alloy products (rolled sheet, extrusions) is an important problem for aluminum industry - more than half of all customer rejec-tions occur not because of inadequate mechanical and physical properties of the manufactured products, but due to the unacceptable quality of product surfaces. The problems to be addressed by this collaboration are generic to aluminum industry, but the effort to develop basic atomic-scale scientific understanding of the relevant processes goes beyond the capabilities of individual corporations. The results will be cast in a form that is usable by industrial researchers who focus on product development. The team includes partners from universities (Vanderbilt and Alabama A&M University), industry (Alcoa Inc.), and Oak Ridge National Laboratory (ORNL). Other collaborators at the Russian Academy of Sciences will also be involved. The new knowledge will provide valuable guidance to the aluminum industry to control its production techniques to achieve desirable optical properties of aluminum products, as specified by customers. This new knowledge will also be captured into modules suitable for high schools and the public by high-school teachers that will spend several summer sessions at Vanderbilt, coordinated by Vanderbilt's Center of Science Outreach. Students engaged in research, including minority students from Alabama A&M University (a historically black university) will visit and work in a national lab (ORNL) and in an industrial setting (Alcoa Technical Center). TECHNICAL DETAILS: The problem of visual appearance and overall quality of the surface (bright-ness, distinctness of image, iridescence, and coloration) is a multiscale problem, linking the atomic-scale structure and chemical composition of the surface and subsurface regions and the meso-scale surface roughness to macroscopic optical properties. Though the phenomenological optics of light scattering from rough surfaces is well developed, the atomic-, nanometer- and micron-scale mecha-nisms that affect optical properties and visual appearance of specific surfaces and the roles of surface oxides, dopants, and defects remain wide open. An interdisci-plinary team will use a combined experimental and theoretical multiscale ap-proach to unravel these issues in a systematic way and provide a scientific basis for dealing with a costly industrial problem. The problem will be addressed using a broad combination of experimental and theoretical tools such as atomic-resolution Z-contrast transmission electron microscopy, EXAFS, atomic force microscopy (AFM), scanning near-field optical microscopy (SNOM), and laser-induced break-down spectroscopy (LIBS) supplemented by first-principles theory and computer simulations. Continuous feedback between experiment and theory at different length scales and the rich database of phenomenological information provided by Alcoa scientists will aim for a cutting-edge demonstration of multiscale, industry-relevant, basic research. The proposed research provides unique opportunities for graduate students and post-doctoral associates. They will have exposure to "basic science" research that underlies industrial concerns, and simultaneously participate in joint work with researchers at Alcoa's Technical Center and at the ORNL. Students training in microscopy at ORNL will get an opportunity to work on an electron microscope with the world's highest resolution.