Collaborative Research: Massive Parallel Laser Direct-Write of Sub-micron Dent Array for Quantum Leap of Fatigue Performance

本研究的目的是开发一种高效、准确、低成本的激光直写工艺，用于在精密部件上制造亚微米凹痕阵列，以提高其疲劳性能。将进行协同实验、理论和计算研究。研究方法是开发一种大规模并行激光直写工艺，用于在精密表面上制造亚微米凹痕阵列，并创建一个有限元分析模型，以捕获相关小尺度的力学行为，以了解激光/材料相互作用的机制，并预测凹痕几何形状、瞬态和残余应力以及表面材料性能。表面完整性将被全面表征，包括表面光洁度、凹痕几何形状、残余应力、微/纳米硬度和模量以及微观结构。将在实验室和生产规模上进行滚动接触疲劳试验，以确定亚微米凹痕阵列对部件疲劳寿命的影响。最后，将建立基于物理的滚动接触有限元仿真模型，以阐明在亚微米凹痕阵列存在下的疲劳损伤机制。该项目将为精密零件的激光加工制造创造一个新的知识库。广泛的影响包括高效和经济的表面处理工艺，以高效率、高精度和低成本制造微表面结构，以满足生产需求。这项研究通过提高美国在制造业中的地位来支持经济。这项合作研究将丰富教育基础设施，促进设施共享，传播研究成果，并加强学术界和工业界的研究人员和教育工作者之间的合作和技术转让。此外，这项研究还促进了正在进行的外展活动，包括阿拉巴马州塔斯卡卢萨的谢尔顿州立大学和斯蒂尔曼社区学院，以及德克萨斯州奥斯汀的奥斯汀社区学院，面向科学和工程领域代表性不足的群体的本科生。

The objective of this research is to develop an efficient, accurate, and low-cost laser direct-write process for fabricating a sub-micron dent array on precision components to enhance fatigue performance. A synergistic experimental, theoretical, and computational study will be conducted. The research approach is to develop a massively parallel laser direct-write process for fabricating a sub-micron dent array on precision surfaces, and create a finite element analysis model to capture mechanical behaviors at pertinent small scales to understand the mechanisms of laser/material interactions and predict dent geometry, transient and residual stress, and surface material properties. Surface integrity will be comprehensively characterized, including surface finish, dent geometry, residual stress, micro/nano hardness and modulus, and microstructures. Rolling contact fatigue tests at both lab and production scales will be conducted to determine the effects of a sub-micron dent array on component fatigue life. Finally, a physics-based finite element simulation model of rolling contact will be developed to elucidate fatigue damage mechanisms in the presence of a sub-micron dent array.This project will create a new knowledge base of laser processing for manufacturing precision components. The broad impact includes an efficient and cost-effective surface treatment process for making micro surface structures with high efficiency, high accuracy, and low cost to meet production needs. The research supports the economy by improving the U.S. position in the manufacturing industry. This collaborative research will enrich the education infrastructure, promote facility sharing, disseminate research results, and enhance collaboration and technology transfer between researchers and educators at academia and industry. In addition, this research fosters ongoing outreach activities, including Shelton State University and Stillman Community College in Tuscaloosa, Alabama and Austin Community College in Austin, Texas, to undergraduates from groups that are underrepresented in science and engineering.