Contamination of Coupling Glass and Performance Evaluation of Protective System in Vacuum Laser Beam Welding
Source abstract
Abstract
Vacuum laser beam welding enables deeper penetration depth and welding stability than atmospheric pressure laser welding. However, contaminated coupling glass caused by welding fumes in the vacuum space reduces laser transmittance, leading to inconsistent penetration depth. Therefore, a well-designed protective system is indispensable. Before designing the protective system, the contamination phenomenon was quantified and represented by a contamination index, based on the coupling glass transmittance. The contamination index and penetration depth behavior were determined to be inversely proportional. A cylindrical protective system with a shielding gas supply was proposed and tested. The shielding gas jet provides pressure-driven contaminant suppression and gas momentum-driven contaminant dispersion. The influence of the shielding gas flow rate and gas nozzle diameter on the performance of the protective system was evaluated. When the shielding gas flow was 2.0 L/min or higher, the pressure-driven contaminant suppression dominated for all nozzle diameters. When the shielding gas flow was 1.0 L/min or lower, gas momentum-driven contaminant dispersion was observed. A correlation between the gas nozzle diameter and the contamination index was determined. It was confirmed that contamination can be controlled by selecting the proper gas flow rate and supply nozzle diameter.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Welding Techniques and Residual Stresses · Laser Material Processing Techniques · Ocular and Laser Science Research
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Joining Research Group, Korea Institute of Industrial Technology, Incheon 21999, Korea
Department of Mechanical Engineering, Yonsei University, Seoul 03722, Korea
Department of Mechanical and Materials Engineering, Portland State University, Portland, OR 97201, USA
Funding
Ministry of Trade, Industry and Energy
References (13)
Show source-provided references
1. Chaturvedi, M.C. (2012). Laser Welding of Metals for Aerospace and Other Applications. Welding and Joining of Aerospace Materials, Woodhead publishing. [1st ed.].10.1533/9780857095169 ↗
2. Transient Model for the Keyhole during Laser Welding10.1088/0022-3727/32/15/103 ↗
3. Laser-Hybrid Welding of Ships
4. Fundamental Phenomena in High Power CO_2 Laser (Report II): Vacuum Laser Welding (Welding Physics, Process & Instrument)
5. Laser Beam Welding under Vacuum of High Grade Materials10.1007/s40194-016-0302-3 ↗
6. Jakobs, S. (2015). Laserstrahlschweißen im Vakuum: Erweiterung der Prozessgrenzen für Dickwandige Bleche. [Ph.D. Theses, RWTH Aachen University].10.1002/stab.201510306 ↗
7. Deep Penetration Welding with High-Power Laser under Vacuum
8. Comparative Study on Laser Welding Characteristics of Aluminium Alloy under Atmospheric and Subatmospheric Pressures10.1179/1362171814Y.0000000223 ↗
9. Effect of Reduced Pressure Atmosphere on Weld Geometry in Partial Penetration Laser Welding of Stainless Steel and Aluminium Alloy with High Power and High Brightness Laser10.1179/1362171813Y.0000000182 ↗
10. Cover glass influence on high power fiber laser induced focus shift
11. Munson, B.R., Young, D.F., and Okiishi, T.H. (2001). Fundamentals of Fluid Mechanics, John Wiley & Sons, Inc.. [4th ed.].
12. Beer, F.P., Johnston, E.R., and Clausen, W.E. (2006). Vector Mechanics for Engineers: Dynamics, McGraw-Hill companies, Inc.. [9th ed.].
13. Online focus shift measurement in high power fiber laser welding10.1016/j.phpro.2010.08.073 ↗