The SuperDraco differs from most rocket engines in that its combustion chamber is 3D printed by direct metal laser sintering (DMLS), where complex metal structures are printed by using a laser to build the object out of metal powders one thin layer at a time. The regeneratively-cooled combustion chamber is made of inconel; a family of nickel-chromium alloy thats notable for its high strength and toughness, and is also used in the Falcon 9s Merlin engine.
http://www.gizmag.com/superdraco-test/32292/
Thanks!