Damascus steel enjoys a legendary reputation. It is strong and ductile at the same time because it consists of layers of different iron alloys. In ancient times, this made it the material of choice for sword blades. Now a team from the Max Planck Institute for Iron Research in Düsseldorf and the Fraunhofer Institute for Laser Technology in Aachen has developed a process that allows steel to be produced layer by layer in a 3D printer, with the hardness of each layer being specifically adjusted. Such composite materials could be interesting for 3D printing of aerospace components or tools.
Even Celtic smiths combined various iron alloys to produce the material that later became known as Damascus steel. It owes its name to the trading centre through which the composite material of oriental origin came to Europe. However, while Indian and Arabic damascus were created by a sophisticated smelting process, European smiths developed the art of folding two alloys into many thin layers. The layered structure of Damascus steel can usually also be recognized visually by a characteristic stripe pattern.
Although there are iron alloys available today that are both hard and ductile, they are often not easy to process with 3D printers, the means of choice for many complex or individually designed components. For this reason, scientists at the Max Planck Institute and the Fraunhofer Institute have developed a technique that allows a single starting material to be used directly in 3D printing to produce a steel that is composed alternately of hard and ductile, i.e. soft layers - a kind of Damascus steel.