Which materials iro3d can print?

As explained in SPD method description iro3d printer is material agnostic. But post-processing (baking) for some materials is easier than others because they require different baking temperatures and atmospheres. For example, glass can be baked in an oxidizing atmosphere, such as air. But most metals require a reducing atmosphere to prevent oxidation. Most commonly used reducing atmospheres are hydrogen, carbon monoxide, and hydro-carbons. Hydrogen can be supplied from an external bottle or generator. Carbon monoxide can be produced in-situ by placing some metallurgical coke (carbon) into the crucible or furnace. Hydro-carbons can be either supplied externally (methane, propane, butane, ...) or produced in-situ, by tar, asphalt, polylactide (PLA), polypropylene (PP), acrylonitrile butadiene styrene (ABS), etc.

Generally, non-reactive metals, such as iron, copper, nickel, tin, lead, bismuth, antimony, molybdenum, cobalt, tungsten, palladium, cadmium, silver, gold, and platinum are easy to reduce. Reactive metals, such as aluminum, chromium, beryllium, etc, are difficult to reduce, so, you shouldn't use them in the powder in large concentrations. You can use them in the infill if the atmosphere is not too oxidizing. To help you decide which metals need which atmosphere, see Ellingham diagram or interactive Ellingham diagram. The tables below show some of the materials and atmospheres we have researched or tried so far.

Materials and atmospheres

SPD variant Powder Infill Atmosphere Result
infilling copper copper + tin carbon monoxide (from coke) bronze
infilling copper copper + silver carbon monoxide (from coke) copper + silver
infilling copper zinc vapor carbon monoxide (from coke) porous brass
infilling iron copper carbon monoxide (from coke) iron + copper
infilling iron bronze carbon monoxide (from coke) iron + bronze
infilling iron iron + carbon carbon monoxide (from coke) high carbon steel, or cast iron, or malleable iron
infilling nickel copper carbon monoxide (from coke) Monel
infilling tungsten copper carbon monoxide (from coke) tungsten + copper (good for radiation shielding)
infilling alumina coated with silver bronze carbon monoxide (from coke) alumina + bronze (composite)
infilling alumina aluminum hydrogen or argon alumina + aluminum (composite)
infilling copper copper + aluminum hydrogen + argon aluminum bronze
infilling copper copper + beryllium hydrogen + argon beryllium bronze
infilling iron iron + chromium + nickel hydrogen + argon stainless steel
infilling copper zinc borax brass
sintering glass air porous glass
sintering glass vacuum, then air solid glass