Aluminum Recrystallization Barrier

Use of transition metals such as zirconium or scandium to form finest dispersoids that block grain growth at high temperatures.

Zirconium or scandium in the alloy keeps the grain in aluminum fine. When welding, you heat the material up a lot, and without these additives the grain grows coarse again. That makes the weld and heat-affected zone brittle and weak. So for welded structures, use an alloy with these grain refiners, then the weld stays tough and holds up.

MetallurgieSchweißtechnik