GOALI: Shear Texture and Microstructure Control in Sheet Metal for Enhanced Deformation Processing and Properties

金属板和金属箔被广泛用于或正在考虑用于先进的结构和磁性产品应用。目前，薄板和铝箔的生产是通过多阶段轧制工艺。轧制工艺虽然成熟且规模较大，但对板材属性的控制有限。此外，它们相当耗能，而且受制于高昂的资本成本。通过与三个工业合作伙伴的合作，GOALI研究学术联络机会将发展一类挤压切割工艺的加工科学，从而一步到位地生产薄板和铝箔。同时，挤压切割可以通过控制织构和微观结构来定制板材的特定属性，这是传统轧制工艺不可能实现的。挤压切割技术的成功开发和实施，将为生产轻质镁钛合金和磁性硅铁等高性能薄板提供有效途径。这将是将这些合金用于汽车、生物医疗、航空航天和电力系统应用的关键一步。作为这项研究的补充，还有一个教育和培训计划，其中包括行业实习、在研究生学习和本科生研究实习中培养企业家精神，包括对来自国家聋人技术学院的残疾学生进行培训的新方面。大应变挤压切割工艺可以克服一些关键障碍，这些障碍限制了从先进合金生产薄板和铝箔的轧制范围。挤压切割可以影响板材中强剪切织构和细晶组织的形成。先前的工作已经表明挤压切割的可扩展性，即使对于加工性能较差的合金，如镁和钛也是如此。这些观察结果提出了一种创造具有有趣的结构、磁性和成形性的新板材的范例。项目小组将在初步调查结果的基础上进行四次协调推进。首先，变形科学计划将使用现场高速成像直接测量过程中的应变、应变率和温度场。它将确定如何利用特殊的变形路径来控制纹理和微观结构。其次，将通过织构分析和电子显微镜来分析结构的发展。与细粒结构相结合的新的基于剪切的纹理及其对成形性的影响尤其令人感兴趣。将建立变形、织构和显微组织之间的关联。第三，将通过表征与取向相关的性能，如强度、成形性和磁导率来评估微观结构与性能的关系。最后，通过整合结果，将与行业合作伙伴合作评估生产性能最佳的板材的工艺设计。

Metal sheet and foil are widely used or under consideration for use in advanced structural and magnetic product applications. Currently, sheet and foil are produced by multi-stage rolling processes. Rolling processes, while mature and large-scale, offer only limited control of sheet attributes. Furthermore, they are quite energy intensive and encumbered by high capital costs. In collaboration with three industrial partners, this Grant Opportunity for Academic Liaison with Indstry (GOALI) research will develop the processing science of a class of extrusion-cutting processes to produce sheet and foil in a single step. Simultaneously, the extrusion-cutting can tailor specific attributes of the sheet, via control of texture and microstructure, in ways not possible by the conventional rolling processes. Successful development and implementation of the extrusion-cutting will provide efficient routes for production of high-performance sheet metals of light-weight magnesium and titanium alloys, and magnetic silicon-iron. This will be a key enabling step for use of these alloys in automotive, bio-medical, aerospace and power systems applications. Complementing the research is an education and training program that includes industry internships, fostering of entrepreneurship in graduate study and undergraduate research internships, including a new dimension to training involving physically challenged students from the National Technical Institute for the Deaf.The large-strain, extrusion-cutting processes can overcome some key barriers that limit the scope of rolling for producing sheet and foil from advanced alloys. Specifically, the extrusion-cutting can effect development of strong shear textures and fine-grained microstructures in sheet metals. Prior work has shown scalability of the extrusion-cutting, even for alloys of poor workability such as magnesium and titanium. These observations suggest a paradigm for creating new sheet metals with interesting structural, magnetic and formability properties. The project team will build on the preliminary findings with four coordinated thrusts. First, a deformation science initiative will measure, directly, the process strain, strain rate and temperature fields using in situ high-speed imaging. It will establish how special deformation paths can be exploited to control texture and microstructure. Second, structure development will be analyzed through texture analysis and electron microscopy. New shear-based textures, combined with fine-grained structures, and their effects on formability are of particular interest. Correlations will be established between deformation, texture and microstructure. Third, microstructure-property relationships will be assessed by characterizing orientation-dependent properties such as strength, formability and magnetic permeability. Lastly, by integrating the results, process design for producing sheet with optimal properties will be assessed in collaboration with the industry partners.