Influence of the solidification path of AlMgSi aluminium alloys on the critical strain rate during remote laser beam welding

ABSTRACT

The solidification paths of aluminium alloys have a major influence on the susceptibility to hot cracking during laser beam welding. The model of Rappaz, Drezet and Gremaud allows to predict the susceptibility to hot cracking of an alloy as a function of its solidification path by means of a critical strain rate. The direct relation between the solidification path and the critical strain rate as stated by the model was confirmed experimentally. For this purpose, AlMgSi alloys with different silicon contents were used to obtain laser beam welds, which solidify along different solidification paths. The corresponding critical strain rates were experimentally determined by means of digital image correlation. The low susceptibility to hot cracking of the investigated aluminium alloys, especially designed for remote laser beam welding, could be attributed to the positive influence of their high amount of silicon on the solidification path.

KEYWORDS:

• Hot cracking susceptibility
• remote laser beam welding
• aluminium alloys
• solidification path
• digital image correlation
• critical strain rate

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Rudolf Weber http://orcid.org/0000-0001-8779-2343

Thomas Graf http://orcid.org/0000-0002-8466-073X

Additional information

Funding

This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – [389369540].