Further Studies of Directional Recrystallization Processing

定向再结晶加工的进一步研究

• 批准号: 0217565
• 负责人: Ian Baker
• 金额: $ 30万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0217565&HistoricalAwards=false
• 关键词: Further; Studies; Directional; Recrystallization; Processing

This project is a fundamental study of directional recrystallization processing, the process whereby one or a few grains or crystals nucleate at one end of a specimen and grow along with a moving hot zone. Directional recrystallization has a number of advantages: net-shape processing; potential energy and cost savings compared to directional solidification; and the ability to process materials not amenable to directional solidification. The overall goal is to understand how key microstructural parameters (the size and spacing of particles, and the grain size and orientation) interact with the processing conditions (rate of hot zone movement and temperature) to control the microstructure. How the initial microstructure and processing conditions can be exploited to produce columnar grains or single crystals of a particular orientation will be explored in polycrystalline nickel sheets. The role of particles will be examined in a model system of copper (both single crystals and polycrystals) containing finely-dispersed particles that can coarsen during processing. Determining the role of particle coarsening or dissolution is key to understanding how columnar grains or single crystals can be produced in many commercial alloy systems. The work will involve a close coupling of experiments with computational microstructural simulation of the processing utilizing a front-tracking grain growth model. While working on specific materials, the goal is to understand directional recrystallization processing at a fundamental level so that this generic technology and the associated modeling can easily be applied to many materials. In addition to graduate education, activities with the Women in Science Project and / or Dartmouth Presidential Scholarships will be encouraged to expand participation of a diverse group of undergraduates on this project. In addition, material developed with the aid of a high school teacher will be presented to high school students.

这个项目是定向再结晶工艺的基础研究，定向再结晶工艺是一个或几个颗粒或晶体在样品的一端形核并沿着移动的热区生长的过程。定向再结晶具有许多优点：净形状加工；与定向凝固相比，潜在的能量和成本节约；以及加工不适合定向凝固的材料的能力。总的目标是了解关键的微观结构参数(颗粒的大小和间距，以及颗粒的大小和取向)如何与工艺条件(热区移动速度和温度)相互作用，以控制微观结构。在多晶镍板中，将探索如何利用初始微结构和工艺条件来产生特定取向的柱状晶或单晶。颗粒的作用将在铜(单晶和多晶)的模型系统中进行检验，该模型系统包含可在加工过程中粗化的细小分散的颗粒。确定颗粒粗化或溶解的作用是了解在许多商业合金系统中如何产生柱状晶或单晶的关键。这项工作将包括实验与利用前沿跟踪颗粒生长模型的过程的计算微观结构模拟的紧密结合。在研究特定材料时，目标是在基础水平上了解定向再结晶工艺，以便这种通用技术和相关的建模可以很容易地应用于许多材料。除了研究生教育外，还将鼓励与女性参与科学项目和/或达特茅斯总统奖学金的活动，以扩大不同本科生群体对这一项目的参与。此外，在高中老师的帮助下开发的材料将展示给高中生。