Alexander F. H. Kaplan
Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-971 87 Luleå, Sweden
During laser keyhole welding of thin plates, the melt pool is relatively wide compared to the plate thickness. Under certain conditions, an elongated keyhole can be created and a permanent hole is sometimes left in the weld seam. The generation of such holes is determined by surface tension effects in the melt which can generate a self-sustaining geometry at the rear of the melt pool. The geometry of the shape is known as a catenoid and has clear geometrical limits.
JLA Vol:26 Iss:1 (Laser absorptivity on wavy molten metal surfaces: Categorization of different metals and wavelengths)
A. F. H. Kaplan
Department of Engineering Sciences and Mathematics, Luleå University of Technology, S-971 87 Luleå, Sweden
The absorptivity of a laser beam interacting at grazing incidence with the processing front during laser welding, cutting, or drilling depends on the metal to be processed and on the laser wavelength. The absorptivity on a smooth processing front is homogeneously governed by the angle-dependent operating range of the corresponding Fresnel-curve. In contrast, a wavy processing front strongly modulates the absorptivity across the surface. The calculated absorptivity modulation is presented for five different metals and four laser wavelengths. A ...
Welding Engineering and Laser Processing Centre, Cranfield University MK43 0AL, United Kingdom
Aluminum, mild steel, and stainless steel have very dissimilar thermal properties. This study focuses on the effect of power density on the laser welding conduction mode limit in these three materials. The objective is to evaluate how these different materials will behave in conduction mode and in keyhole mode and also to understand how the thermal properties of the materials will influence the transition between the different welding modes. A comparison between the penetration depth and the melted area for the different materials under ...
Iranian National Centre for Laser Science and Technology (INLC), PO Box 14665-576 Tehran, Iran and Department of Physics, Amir Kabir University of Technology, PO Box 15875-4413 Tehran, Iran
Department of Physics, Amir Kabir University of Technology, PO Box 15875-4413 Tehran, Iran
Mohamad Javad Torkamany
Jamshid Sabbagh Zadeh
Iranian National Centre for Laser Science and Technology (INLC), PO Box 14665-576 Tehran, Iran
A two-dimensional thermal model of nanosecond pulsed laser ablation is developed to describe the physical processes, the plasma absorption, the crater profile, and the temp...
JLA Vol:26 Iss:1 (Periodic antireflection surface structure fabricated on silicon by four-beam laser interference lithography)
CNM and JR3CN, Changchun University of Science and Technology, Changchun 130022, China and CHO, Changchun Observatory, National Astronomical Observatory, CAS, Changchun 130117, China
CNM and JR3CN, Changchun University of Science and Technology, Changchun 130022, China and JR3CN, University of Bedfordshire, Luton LU1 3JU, United Kingdom
CNM and JR3CN, Changchun University of Science and Technology, Changchun 130022, China
Silicon surface structures with excellent antireflection property arouse wide interest. Chemical and physical methods such as femtosecond, nanosecond, and picosecond la...
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