Researchers from Northwestern University in Illinois have developed a new technique to print 3-D metallic objects using rust and metal powders. While current printing techniques make use of metal powder beds and lasers or electron beams, the new technique uses liquid inks and common furnaces. The end result is less expensive, faster, and a more uniform process. The system has also been demonstrated to work with an array of metals, metal mixtures, alloys, and metal oxides and compounds. The new technique prints by creating a liquid ink made of metal or mixed metal powders, solvents, and an elastomer binder. Using this, the researchers have been able to print densely packed powder structures using a syringe-extrusion process in which ink is dispensed through a nozzle at room temperature. The extruded material instantaneously solidifies and fuses with previously extruded material, and then the structure is heated in a furnace for sintering – merging the powders together without melting.
source: Northwestern University