Influence of Laser-Induced Bubble Formation on Laser Chemical Machining

• 作者: Frank Vollertsen Marcel Simons Raj Shanta Kajsaravally Tim Radel
• 来源期刊: 表面工程材料与先进技术期刊(英文)
• 学科: 工学
• 关键词: MICRO MACHINING LASER MICRO MACHINING LASER CHEMICAL Removal Nucleate BOILING Highspeed Videography
• 年，卷（期）: 2020,（2）
• 页码范围: 21-33
• 页数: 13页
• 分类号: TG1

摘要

Laser Chemical Machining (LCM) is a non-conventional processing method, which enables very accurate and precise ablation of metallic surfaces. Material ablation results from laser-induced thermal activation of heterogeneous chemical reactions between electrolytes and a metallic surface. However, when processing metallic surfaces with LCM, large fluctuations in ablation quality can occur due to rising bubbles. The for-mation of bubbles during laser chemical machining and their influence on the ablation quality has not been investigated. For a more detailed investigation of the bubbles, ablation experiments on Titanium and Ce-ramic under different thermal process conditions were performed. The experiments were recorded by a high-speed camera. The evaluation of the video sequences was performed using Matlab. The resulting bubbles were analyzed regarding their size and frequency. The results show that boil-ing bubbles formed on both materials during processing. Titanium also produces smaller bubbles, which can be identified as process bubbles ac-cording to their size. Furthermore, it was found that undisturbed laser chemical ablation can be achieved in the presence of a boiling process, since both boiling bubbles and process bubbles were detected during machining within the process window.