Aluminum

Pure aluminum is a very ductile metal. It forms a large number of alloys with the different alloying elements (Cu, Mn, Si, Mg, and Zn). Their different mechanical properties depends on the type of their microstructure resulting from the chemical composition and the type of cold hardening or the heat treatment cycle. Aluminum products are derived either from casting or wrought processes. Wrought alloys are in turn grouped into two classes: heat treatable (precipitation hardening) alloys (2xxx, 6xxx and 7xxx series) and Non-Heat-Treatable (cold hardening) alloys.

• porosity due non dissolved hydrogen from the base metal (hydrated aluminum oxide), shielding gas, flux coating, etc;
• hot cracking which does not depend on impurities but rather on the composition of the alloy;
• weakening of mechanicals strength of the metal (HAZ)