This thesis examines the influence of filler material chemical composition on the quality of
pulsed laser butt welds between extruded EN AW-6063 alloy and die-cast EN AC-AlSi9Cu3
or EN AC-AlSi10Mg alloy. The filler materials compared were AlSi12, AlSi5, AlSi7Mg,
and AlMg5. Weld quality was assessed by visual inspection, radiographic analysis,
metallographic cross-section examination, microhardness measurements, and a pressure leak
test at a pressure of 6 bar. The results show that filler materials with a higher silicon content
provided a more stable process and lower porosity. No cracks were detected in any of the
tested combinations, which was attributed mainly to the high silicon content of the cast alloys
and the high dilution ratio. The addition of magnesium increased spatter and porosity due to
its volatility at high energy densities. For the application under consideration, AlSi12 proved
to be the most suitable choice, with the effects of dilution, joint geometry, and base material
of the casting all needing to be taken into account.
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