Comment by Tuna-Fish

The search space is much, much more vast than you'd imagine, and there are so many ways that things get non-linear that we have absolutely no idea how (way) more than 99.9999% of the possible alloys that we could make would actually perform in reality. The way most of the alloys we are using were found was that we started with something that we already knew, and then tweaked from there to optimize some property.