[HPsquared]

So you need to control the solidification process to plot a course through the phase diagram, spending the right amount of time in each region, and ending up in a good place. And this alloy has a phase diagram that is compatible with a method of 3d printing.

[pfdietz]

I think this is also why welding aluminum alloys was such a pain before the introduction of friction stir welding, which doesn't melt the metal. FSW was invented surprisingly late, in the 1990s.