The printer itself is material agnostic, and can pour any powder that flows though a small hole.
SPD can work with any metal combinations where the infill metal has lower melting temperature than the powder and the final alloy.
Though, different metals require different baking temperatures and atmospheres.
Hydrogen-argon atmosphere would work with pretty much any metal.
But such furnaces are very rare and thus expensive.
On the other hand, carbon oxide atmosphere is very easy to produce (by placing coke into the crucible), and according to the
it works well for non-reactive metals, such as
iron, copper, nickel, tin, lead, bismuth, molybdenum, cobalt, tungsten, palladium, cadmium, silver, gold, platinum.
But carbon oxide has a problem - over the time, it deposits soot onto the powder, which interferes with the infill process.
Another alternative is to use a soldering flux. But soldering fluxes work only with low melting temperature metals, such as tin, lead, and bismuth.
But brazing fluxes might work with higher temperatures. We need to research them.
We have also looked into infilling ceramics powders with aluminum and other metals, and found
many good artiles
But to try them we would need a furnace with a controlled atmosphere: hydrogen, argon, nitrogen, or vacuum.
And sepaking of controlled atmosphere furnaces again - it's not that difficult to make one. And much cheaper than buying it.
But it's a separate project. Anyone wants to collaborate?