Why is an aluminium alloy stronger than pure aluminum?
lolitahe69 > 12-14-2021, 07:58 AM
Most alloys are stronger than the pure metals. A lot of the aluminium alloys are precipitation hardening, meaning that there are small grains of harder material that block the movement of imperfections (dislocations) that are what deformation is about. … If you think of deformation as moving a rug through the material, the dislocations are like a little fold on the rug and it is much easier to move the fold than pulling the entire rug. Now, a precipitate, for example a magnesium silicide particle, act a bit like a nail through the carpet and effectively stops you from pushing the carpet fold along.
There are other hardening mechanisms, but most boil down to small areas being harder than the rest and very locally making it more complicated for the deformation to carry on through the material.