CAREER: The Role of Grain Boundary Character in Corrosion Behavior: Linking Atomic Scale Interfacial Structure to Precipitation and Failure Mechanisms

本学院早期职业发展（Career）计划奖的目标是发展对fcc金属中增强腐蚀沉淀的原子尺度晶界结构依赖的理解。腐蚀对许多工业都有毁灭性的影响，包括核工业、海军舰船结构和海上风力涡轮机。晶界工程已被证明可以改善与晶界相关的性能，包括蠕变、晶间应力腐蚀、脆化和疲劳。然而，关于fcc材料中与所有敏化相关的失效相关的偏析和沉淀的各向异性的问题仍然存在。该项目将重点了解晶界结构对引起腐蚀损伤的沉淀的依赖。这项研究的结果将作为预测工具，用于开发未来在极端环境中抵抗有害晶间析出的合金。这项工作将使用实验方法来分析温度、环境和晶界类型对引起腐蚀的沉淀机制的综合影响，这将最终使人们对各种合金的腐蚀有更清晰的认识。该研究有望促进对fcc金属腐蚀失效机制的基本认识，fcc金属是当今最重要的结构材料之一。费城约有80%的少数族裔学生，因此将代表性不足的群体带入STEM领域的机会是巨大的。PI计划开发一个名为“TURBINE”（改造工程中代表性不足的研究基础）的项目，让当地的高中少数族裔和女学生了解能源相关领域的未来职业，以激发对费城和全球未来经济的研究、开发和工程教育/培训的兴趣。

The objective of this Faculty Early Career Development (CAREER) Program award is to develop an understanding of the atomic scale grain boundary structure dependence of corrosion enhancing precipitation in fcc metals. Corrosion has a devastating effect on many industries, including nuclear, naval ship structures, and off-shore wind turbines. Grain boundary engineering has been shown to improve boundary dependent properties including creep, intergranular stress corrosion, embrittlement, and fatigue. However, questions remain about the anisotropic nature of both the segregation and precipitation relevant to all sensitization dependent failure in fcc materials. This project will focus on understanding the dependence of grain boundary structure on the precipitation that causes corrosion damage. The results generated from this study will serve as a predictive tool for developing future alloys resistant to deleterious intergranular precipitation in extreme environments. The work will use an experimental approach to analyze the combined effects temperature, environment, and grain boundary type on corrosion-causing precipitation mechanisms, which will ultimately yield a clearer understanding of corrosion in a wide range of alloys.This research is expected to advance the fundamental understanding of mechanisms of fcc metal failure under corrosion, one of the most important structural materials in use today. Philadelphia has ~80% minority student population, so the opportunity to bring underrepresented groups into STEM fields is enormous. The PI plans to develop a program, named "TURBINE" (Transforming Underrepresented Research Basis in Engineering), for local high school minority and female students to learn about future careers in energy-related fields to spur an interest in research and development and engineering education/training for a future economy both in Philadelphia and globally.