학술논문

Synchrotron X-ray imaging of the formation of geometry deviations during percussion laser drilling with ultrashort pulses
Document Type
Academic Journal
Source
Journal of Laser Micro Nanoengineering. September, 2024, Vol. 19 Issue 2, p151, 4 p.
Subject
Germany
Language
English
ISSN
1880-0688
Abstract
The main objective of this work is to provide a basic understanding of the mechanisms and locations of defect formation during percussion laser drilling of microholes using ultrashort pulses. Through the application of high-speed synchrotron X-ray imaging, we have been able to observe the dynamic formation and evolution of these defects in real-time. Our findings indicate that the initial deviations in the borehole geometry are highly dependent on the applied laser fluence. Specifically, while higher peak fluences facilitate deeper drilling, there exists a critical threshold beyond which the position of these deviations begins to decrease as the fluence increases. This behavior can be partially predicted within a certain fluence range using an existing theoretical model, which our experimental observations have tested and validated. Consequently, this research not only advances our understanding of defect formation in laser drilling but also provides a predictive framework for optimizing drilling parameters to minimize defects and enhance borehole quality. Keywords: laser drilling; process observation; high-speed X-ray imaging; ultra-short pulses; side channel formation;
1. Introduction The analysis of microholes in stainless steel, with respect to lateral extensions such as bulges and side channels, contingent on the polarization of the laser beam, has been [...]