11 Dokumente gefunden

Temporal and spatial determination of solidification rate during pulsed laser beam welding of hot-crack susceptible aluminum…

Pulsed laser beam welding is primarily used to join thin-walled components. The use of 6xxx group aluminum alloys is characterized by good mechanical properties but these alloys are prone to hot cracking during solidification, i.e., requirements regarding strength and tightness, as increasingly important…
Amsterdam: Elsevier, 2024-06-24

Reducing capillary depth fluctuations in high-speed laser welding of stainless steel using multi-core laser technology

Laser welding was carried out in AISI304 (X5CrNi18-10) stainless steel using a multi-core fiber laser. High-speed X-ray imaging was used to monitor the process. When employing core-power only (400W) at high welding speeds (12m/min), the capillary depth was found to be inconsistent. The capillary penetration…
Amsterdam: Elsevier, 2024

Insight into keyhole and melt pool dynamics in laser welding of zinc-coated steels by means of high-speed synchrotron X-ray…

Laser welding zinc-coated steels is of major importance in automotive engineering and other industries to ensure cost-effective corrosion resistance of assemblies without requiring post-weld rework. However, the low evaporation temperature of zinc is causing welding defects, in particular melt ejections…
Amsterdam: Elsevier, 2024

Effect of concentric intensity distributions on spatter formation in full penetration welding of high-Alloy steels

Welding of high-Alloy steels results in spatter formation addressing high welding speeds above 8 m/min, i.e., the seam quality is significantly reduced due to material losses and adhering spatter. A reduction of spatter can be addressed by using concentric intensity distributions consisting of core and…
Amsterdam: Elsevier, 2024

Describing the effect of local gas flow on keyhole and melt flow dynamics utilizing high-speed synchrotron X-ray imaging…

Laser beam welding with partial gas shielding using local gas flows has been shown to be very effective in reducing spatter, especially when welding high-Alloy steels at high processing speeds (≥ 8 m/min). This paper examines the gas flow induced mechanical effect on keyhole geometry and correlating…
Amsterdam: Elsevier, 2024

Effect of partial and global shielding on surface-driven phenomena in keyhole mode laser beam welding

Partial shielding by means of local gas supply has proven to be very effective in reducing spatter. Besides the effect of gas-induced dynamic pressure, the shielding of oxygen is also highly relevant for melt pool dynamics and spatter formation due to the growth of oxides and the influence on surface…
Berlin: Springer, 2023-12-01

Interaction between local shielding gas supply and laser spot size on spatter formation in laser beam welding of AISI 304

Background. Spatter formation at melt pool swellings at the keyhole rear wall is a major issue for laser deep penetration welding at speeds beyond 8 m/min. A gas nozzle directed towards the keyhole, that supplies shielding gas locally, is advantageous in reducing spatter formation due to its simple utilization.…
Basel: MDPI, 2023-09-20

Understanding the formation of “false friends” (hidden lack of fusion defects) in laser beam welding by means of high-speed…

This paper provides a fundamental understanding of “false friend” formation, i.e., hidden defects associated with lack of fusion, using an experimental setup that allowed an insight into the processing zone based on high-speed synchrotron X-ray imaging. The setup enabled the welding of a lap joint of…
Berlin: Springer, 2023-09-18

Effect of local pressure distribution on spatter formation for welding high alloy steel at high welding speeds

Laser beam welding with solid-state lasers leads to the formation of spatters at relevant processing speeds (≥ 8 m/min). The use of local gas flows proved to be adequate to avoid these phenomena. This publication examines the mechanical effect of a local supply of argon, nitrogen and helium to provide…
[Amsterdam u.a.]: Elsevier BV, 2022-09-06

Characterization of keyhole dynamics in laser welding of copper by means of high-speed synchrotron X-ray imaging

Laser welding of copper is of great importance for industrial applications, e.g., for manufacturing of electrical components such as hairpins. Solid state lasers are widely used due to the high power and beam brilliance, but the implementation can be challenging in terms of process instabilities and…
[Amsterdam u.a.]: Elsevier BV, 2022-09-06

Evaluation of the effect of local gas flows on keyhole geometry by means of a half-section setup

Increasing beam power of solid-state lasers enables high welding speeds for laser welding processes. However, increasing welding speeds lead to imperfections, especially spatter formation while processing high-alloy steels. A recent and novel approach to reduce the spatter formation is the utilization…
[Amsterdam u.a.]: Elsevier BV, 2022-09-06