U.S.-Egypt Cooperative Research: Modeling of Welding of Titanium Alloys

0711136 DebRoy描述：该项目支持T. DebRoy，材料科学与工程系，宾夕法尼亚州立大学，大学公园，宾夕法尼亚州，与Abdel-Moneim El-Batahgy博士，中央冶金研究发展学院，埃及赫勒万合作。他们计划研究钛合金的焊接。PI计划进行合作实验和理论研究，以促进对复杂焊接工艺和焊接材料的基本理解。本文研究了Ti-6Al-4V合金焊接过程中晶粒组织和显微组织的变化。特别是，温度和速度场，冷却速率和凝固参数在激光束焊接过程中将通过数值解的质量，动量和能量守恒方程在三维计算。计算的温度场将与可用的Monte Carlo晶粒生长计算程序相结合，以了解在Ti-6Al-4V焊缝的热影响区的晶粒结构和拓扑结构的演变传导和小孔模式激光束焊接。此外，在激光束和GTA焊接Ti-6Al-4V合金的热影响区的显微组织将检查的基础上计算的温度场和独立的相变动力学数据在文献中。焊接件将由埃及团队进行广泛的表征。智力优势：所提出的工作的目标是获得更深入的了解钛合金的微观结构在焊接过程中经历的变化。这是一个重要的问题;它具有根本的科学意义以及潜在的经济和技术相关性。正在考虑的材料是一个很好的例子，具有不同的应用，是一个很好的选择。能够预测焊缝显微组织的目标是值得注意的，从拟议的工作的结果将是有价值的许多学科。PI开发的模型是一流的，适用于手头的问题。更广泛的影响：深入了解焊接对钛合金显微组织的影响可能会带来经济效益和钛技术的进步。研究结果可能会包含在计算材料科学的研究生课程中。将研究与教学相结合，并为宾夕法尼亚州立大学和埃及的本科生和研究生提供严格的培训是可能的结果。 宾夕法尼亚州立大学的PI部门积极促进妇女和少数民族学生和学者的教育机会。焊接技术的进步对基础设施和生活水平至关重要。研究结果将有助于焊接向公认的主流工程科学的转变。最后，通过宾州州立大学现有的推广计划，许多与宾州州立大学有互动的行业也会对研究结果感兴趣。该项目得到了美国-埃及联合基金方案的支持，该方案向两国的科学家和工程师提供赠款，以开展这些合作活动。

0711136DebRoyDescription: This project supports collaborative research by Dr. T. DebRoy, Materials Science and Engineering Department, Pennsylvania State University, University Park, Pennsylvania in collaboration with Dr. Abdel-Moneim El-Batahgy, Central Metallurgical Research & Development Institute, Helwan, Egypt. They plan to study the welding of titanium alloys. The PIs plan a collaborative experimental and theoretical investigation to advance fundamental understanding of both the complex welding processes and welded materials. Development of the grain structure and microstructure during welding of Ti-6Al-4V alloy will be investigated. In particular, temperature and velocity fields, cooling rates and solidification parameters during laser beam welding will be calculated through numerical solution of the equations of conservation of mass, momentum and energy in three dimensions. The computed temperature fields will be combined with an available Monte Carlo grain growth calculation program to understand the evolution of the grain structure and topology in the heat affected zone of Ti-6Al-4V welds for both conduction and keyhole mode laser beam welding. In addition, the microstructure in the heat affected zone of both laser beam and GTA welded Ti-6Al-4V alloys will be examined based on the computed temperature fields and the independent phase transformation kinetic data available in the literature. The weldments will be characterized extensively by the Egyptian team. Intellectual Merit: The goal of the proposed work is to obtain deeper insight into the changes that the microstructure of titanium alloys undergoes during welding. This is an important problem; it is of fundamental scientific interest as well as potential economic and technological relevance. The material being considered is an excellent example with varied applications and is an excellent choice. The objective of being able to predict the weld microstructures is noteworthy and the results from the proposed work will be of value to many disciplines. The models developed by the PI are first rate and are suitable for the problem at hand. Broader impacts: Deeper insights into the effect of welding on the microstructure of titanium alloys may lead to economical benefits and progress in titanium technology. The results many be included in a graduate course on computational materials science. Integrating research in teaching, and providing rigorous training for undergraduate and graduate students at Penn State and in Egypt are likely outcomes. The PI''s department at Penn State aggressively promotes educational opportunity to women and minority students and scholars. Advances in welding technology are crucial for infrastructure and standard of living. The results will contribute to the transformation of welding to a well-accepted mainstream engineering science. Finally the results will also be of interest to many industries that has interaction with Penn State through existing outreach programs at Penn State. This project is being supported under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to carry out these cooperative activities.