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

金属薄板和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，薄板和箔是由多阶段轧制工艺生产的。轧制工艺，虽然成熟和大规模，只提供有限的控制板材的属性。此外，它们是相当能源密集型的，并受到高资本成本的阻碍。在与三个工业伙伴的合作下，这项与工业学术联络的资助机会（GOALI）研究将发展一类挤压切割工艺的加工科学，从而在一个步骤中生产薄板和箔。同时，挤压切割可以通过控制纹理和微观结构来定制板材的特定属性，这是传统轧制工艺无法做到的。挤压切削技术的成功开发和实施将为轻质镁、钛合金、磁性硅铁等高性能板材的生产提供有效的途径。这将是在汽车、生物医学、航空航天和电力系统应用中使用这些合金的关键一步。与这项研究相辅相成的是一项教育和培训计划，其中包括工业实习、研究生学习和本科生研究实习中的创业精神培养，包括国家聋人技术研究所的残疾学生的新培训。大应变、挤压切削工艺可以克服一些关键障碍，这些障碍限制了用先进合金生产薄板和箔的轧制范围。具体来说，挤压切削可以影响板料中强剪切织构和细晶显微组织的发展。先前的工作已经证明了挤压切削的可扩展性，甚至对镁和钛等易加工性差的合金也是如此。这些观察结果为创造具有有趣结构、磁性和可成形性的新金属板材提供了一个范例。项目小组将在初步调查结果的基础上开展四项协调工作。首先，一项变形科学倡议将使用原位高速成像直接测量过程应变、应变速率和温度场。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，通过织构分析和电子显微镜分析结构发育。新的基于剪切的纹理，结合细粒结构，以及它们对成形性的影响是特别感兴趣的。将建立变形、织构和显微组织之间的相关性。第三，将通过表征取向相关的特性（如强度、成形性和磁导率）来评估微观结构-性能关系。最后，通过整合结果，将与行业合作伙伴一起评估生产具有最佳性能的板材的工艺设计。

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.