Simulation of time-dependent pool shape during laser spot welding: Transient effects

Georg Ehlen, Andreas Ludwig, Peter R. Sahm

Research output: Contribution to journalArticleResearchpeer-review

34 Citations (Scopus)

Abstract

The shape and depth of the area molten during a welding process is of immense technical importance. This study investigates how the melt pool shape during laser welding is influenced by Marangoni convection and tries to establish general qualitative rules of melt pool dynamics. A parameter study shows how different welding powers lead to extremely different pool shapes. Special attention is paid to transient effects that occur during the melting process as well as after switching off the laser source. It is shown that the final pool shape can depend strongly on the welding duration. The authors use an axisymmetric two-dimensional (2-D) control-volume-method (CVM) code based on the volume-averaged two-phase model of alloy solidification by Ni and Beckermann and the SIMPLER algorithm by Patankar. They calculate the transient distribution of temperatures, phase fractions, flow velocities, pressures, and concentrations of alloying elements in the melt and two solid phases (peritectic solidification) for a stationary laser welding process. Marangoni flow is described using a semiempirical model for the temperature-dependent surface tension gradient. The software was parallelized using the shared memory standard OpenMP.
Original languageEnglish
Pages (from-to)2947-2961
Number of pages15
JournalMetallurgical and materials transactions. A, Physical metallurgy and materials science
Volume34.2003
Issue number12
DOIs
Publication statusPublished - Dec 2003

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