Department of Future Convergence Engineering, Cheonan College of Engineering, Kongju National University, Cheonan, 31080, South Korea.
Department of Mechanical and Automotive Engineering, Cheonan College of Engineering, Kongju National University, Cheonan, 31080, South Korea.
Sci Rep. 2023 Feb 4;13(1):2048. doi: 10.1038/s41598-023-28700-2.
A laser processing technique is proposed for the processing of a 2.5 mm thick carbon nanotube (CNT) composite bipolar plate for proton exchange membrane fuel cells (PEMFCs). This study aims to understand laser interaction with the CNT composite plate experimentally using a pulsed nanosecond laser. Penetration depth, top width, spatter width, and overall physical morphologies are studied. Scanning electron microscope (SEM) and 3D Scanning Confocal Microscope were used for observation and measurements. Based on that, a parametric investigation is conducted and reported systematically. Most importantly, the pulse repetition rate presents a unique nature of interaction that resulted in a critical repetition rate distinguishing three operational regimes. The physical and chemical properties of the regimes are further analyzed by Vickers microhardness testing and energy dispersive X-ray (EDX) analyses performed on the surface and cross-section of each specimen. The results reveal that the pulse repetition rate introduces changes in mechanical properties and chemical compositions in the vicinity of the processed region. In conclusion, lower pulse repetition should be favored for less impact on mechanical properties, chemical composition, and morphological aspects.
提出了一种激光加工技术，用于加工 2.5 毫米厚的用于质子交换膜燃料电池 (PEMFC) 的碳纳米管 (CNT) 复合双极板。本研究旨在使用纳秒脉冲激光从实验上理解激光与 CNT 复合板的相互作用。研究了穿透深度、顶部宽度、飞溅宽度和整体物理形貌。使用扫描电子显微镜 (SEM) 和 3D 扫描共聚焦显微镜进行观察和测量。在此基础上，进行了参数研究，并系统地进行了报告。最重要的是，脉冲重复率呈现出独特的相互作用性质，导致存在一个区分三种操作模式的临界重复率。通过对每个试件的表面和横截面进行维氏显微硬度测试和能量色散 X 射线 (EDX) 分析，进一步分析了各模式的物理和化学性质。结果表明，脉冲重复率会导致加工区域附近的机械性能和化学成分发生变化。总之，较低的脉冲重复率应该更有利于减少对机械性能、化学成分和形貌的影响。
