There are movies detailing samurai swords cutting through other steel, and knives that have supernatural abilities; these movies, while fantastic, are just that, fantasy. In this article, we will explore the history, composition, and benefits of this amazing material. The steel can be identified easily by the pattern etched into the face of the material, but the pattern does not always have to be present.
Damascus is the composite of a minimum of two different metals forged beaten while glowing hot together. Usually, one metal has a high carbon alloy and the second metal is lower in carbon. High carbon steel has a very strong, but brittle characteristic; this can be helpful in the case of knives for maintaining an edge. The low carbon steel is much more ductile pliable and helps the blade flex and absorb impact. As a result, the forging process creates an alloy with the combined characteristics of the metals such as flexibility from one and strength from the other.
Another interesting Damascus pattern: "Raindrops" on one of Olamic Suna knives. The resulting material also has an aesthetically pleasing appearance on the surface that is wholly dependent on the blacksmith and the forging process. The acid does not compromise the steel in any way, it only shows a more complete boundary between the folds of the metal. This process is not required for the strength of the steel and is only for visual purposes. This process has been replicated in older firearm barrels for shotguns, and although it is beautiful, and Damascus steel knives are very strong, these barrels are not known for their strength and should be avoided: the pressures involved in a firearm barrel are very different than those applied to a knife.
To further characterize Damascus steel, one needs to look at the composition and the mixing. More layers are the answer to better steel, which comes from more folding during the forging process. This will create steel with properties that lie between the two materials. By limiting the layers and proportions of the metals, the blacksmith can regulate the properties of the steel accordingly. The quality of the folded steel depends almost exclusively on the way the layers are forged together and any separation between the layers.
Oxidation of the layers as they are forged together can cause enormous issues with breakage, further oxidation, and other unpredictable mechanical qualities. A research team in found, using x-ray and electron microscopy, that original Damascus steel produced long ago actually contains carbon nanotubes and cementite nanowires.
