CAREER: Twinning Induced Grain Boundary Engineering In Ultrafine Grain Materials: A Multidisciplinary Approach

职业：“超细颗粒材料中的孪晶诱导晶界工程：多学科方法”，德克萨斯农工大学机械工程系易卜拉欣·卡拉曼摘要对固体界面含量和结构的操纵可以被认为是材料进化中最重要的过程之一。由于界面的体积分数很大，这对于控制超细颗粒材料(晶粒度为1 mm)的物理和力学性能尤为重要。这一职业计划旨在开发新的孪晶诱导晶界工程(GBE)策略，加深对UFG材料中孪晶诱导晶界工程的理解，并利用综合的研究和教育方法，发展对由晶界及其内部控制的材料性能的预测和控制能力。研究计划集中在三个主要领域：1)加工：通过严重塑性变形处理制备UFG材料，然后从粉末前体或块体前体开始进行热处理，以改变晶界和织构的结构和比例；2)表征：晶界特征分布、织构、利用独特的实验技术，如取向成像显微镜和原位中子衍射仪，建立材料内部应力分布模型；3)建模：开发一种跨长度尺度的分层结构材料建模方法，以预测UFG材料的力学性能和微观结构演化。重点介绍了低层错能高强度钢的形变和退火孪生诱导界面。这项研究计划意义重大，因为尽管控制晶界特征很重要，但从来没有一项将GBE和块状UFG材料结合起来并调查孪生效应的研究。教育计划是通过开发严格的金属材料课程，并通过激励和准备长期为UFG材料工程做出贡献的学生作为工程师和研究人员来加强德克萨斯农工大学(TAMU)的材料工程学院。由于微型材料世界对公众来说是陌生的，特别是年轻的，尽管它有所有迷人的发展，将付出巨大的努力来弥合这一差距。将与一所地区高中合作开发一个试点教学单元，为学生提供实物感受和材料实践体验。

CAREER: "Twinning Induced Grain Boundary Engineering In Ultrafine Grain Materials: A Multidisciplinary Approach"Ibrahim KaramanDepartment of Mechanical Engineering, Texas A&M UniversityAbstractThe manipulation of the interface content and structure of solids can be considered as one of the most important processes in the evolution of materials. This is particularly important for controlling the physical and mechanical properties of ultrafine grain materials (UFG) (grain size 1 mm) because of the large volume fraction of interfaces. This CAREER program aims at developing new strategies for twinning induced grain boundary engineering (GBE), furthering the understanding of GBE in UFG materials, and developing predictive and control capabilities for the materials properties that are governed by grain boundaries and their interiors, utilizing an integrated research and education methodology.The RESEARCH PLAN focuses on three thrust areas: 1) processing: fabrication of UFG materials by severe plastic deformation processing followed by thermal treatments starting either from powder precursors or bulk precursors to vary the structure and fraction of the boundaries and the texture, 2) characterization: microstructural characterization of boundary character distribution, texture, and internal stress distribution utilizing unique experimental techniques such as orientation imaging microscopy and in-situ neutron diffraction, 3) modeling: developing a hierarchically structured materials modeling approach across length scales to predict the mechanical properties and microstructural evolution of UFG materials. Specific emphasis will be given to deformation and annealing twinning induced interfaces in low stacking fault energy, high strength steels. The research plan is SIGNIFICANT because, despite the importance of controlling the grain boundary character, there has never been a study combining GBE and bulk UFG materials and investigating the effect of twinning.The EDUCATION PLAN is to strengthen the faculty of materials engineering at Texas A&M University (TAMU) by developing a rigorous curriculum on metallic materials, and by motivating and preparing students who can contribute to UFG materials engineering on a long-term basis both as engineers and researchers. Since the micro materials world is a stranger to public, particularly the younger ones, in spite of all its fascinating developments, a significant effort will be put to bridge this gap. A pilot instructional unit will be developed, in collaboration with an area high school, to offer students a physical feel and hands-on experience with materials.