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

金属板和箔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，片材和箔通过多阶段轧制工艺生产。轧制工艺虽然成熟且大规模，但仅提供有限的板材属性控制。此外，它们是相当能源密集型的，并受到高资本成本的阻碍。在与三个工业合作伙伴的合作中，这个与工业学术联络（GOALI）研究的资助机会将开发一类挤出切割工艺的加工科学，以便在一个步骤中生产板材和箔材。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，这是传统轧制工艺所不可能实现的。挤压切割技术的成功开发和应用，将为生产高性能的轻质镁、钛合金板材和磁性硅铁板材提供有效途径。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。作为对研究的补充，一项教育和培训计划包括工业实习、培养研究生学习和本科生研究实习中的创业精神，其中包括一个新的培训维度，涉及来自国家聋人技术研究所的身体残疾学生。大应变挤压切割工艺可以克服一些限制先进合金生产板材和箔材轧制范围的关键障碍。具体地说，挤压切割可以影响金属板材中强剪切织构和细晶粒显微组织的发展。先前的工作已经显示出挤压切割的可扩展性，即使对于可加工性差的合金，例如镁和钛。这些观察结果提出了一个范例，创造新的金属板有趣的结构，磁性和成形性能。项目小组将在初步调查结果的基础上开展四项协调一致的工作。首先，变形科学计划将使用原位高速成像直接测量过程应变、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织构和显微组织。其次，通过织构分析和电子显微镜分析结构发展。新的基于剪切的纹理，结合细晶结构，以及它们对可成形性的影响是特别感兴趣的。将在变形、织构和显微组织之间建立相关性。第三，微观结构与性能的关系将通过表征取向相关的性能，如强度，可成形性和磁导率进行评估。 最后，通过整合结果，将与行业合作伙伴合作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.