Already can do. Look at Cold Spray - http://en.wikipedia.org/wiki/Gas_dynamic_cold_spray
We have/had a Cold Spray machine here at work. Not a lot of business for it, so it's not active right now. You could just mix in various titaniums, steels, aluminum and make all types of fun semi-alloys. You could even mix plastic or other materials in there to get some really interesting and crazy materials, but none of them really exhibited true alloy-like characteristics. The most practical thing I saw it do was a local machine shop botched the job on the final pass of this hugely expensive large precision titanium piece that would require them to junk it and start over. We cold-sprayed the gouge back in and then they re-machined it correctly, saving tons of time, money and effort.
Problem is that alloys or unique materials nearly always get their unique properties due to the unique circumstances with which they were formed. There's always interesting steps to ensure that the bonds are as expected, like extreme pressure or heat, being under various gas blankets or fluids when combining, etc.
This is just melty where Cold Spray was deformative.
I mean this is cool. You can make some really neat things, but exotic alloys or new materials is definitely not one of them.Yea, you could stack materials or "thread" them together, but we're already pretty good at that using massive presses.