Laminated-welded steel had its genesis sometime in the beginnings of the iron age. The early smiths of this time period learned that by folding and welding iron in a carbon bearing charcoal fire, that they could produce a new form of iron, since called steel. They quickly realized that a hardenable iron product was capable of producing vastly superior weapons and tools.
Many of the technologically advanced cultures in the ancient world developed some type of laminated or pattern-welded steel. The old Nordic cultures produced swords from the Viking era that clearly show intricate pattern-welding. Perhaps the most aesthetically and technically advanced form was developed in Japan, where the sword became the focal point of an entire civilization. The old Japanese smiths developed a process of smelting and forge welding iron-bearing black sand (iron oxide, satetsu) in a smelter using charcoal as both fuel and the source of carbon. In the smelter, the carbon combined with the iron to produce tamahagane (pronounced tah-mah-hah-gah-nay). The carbon content in this steel was uneven, so the smith would use forge-welding techniques to fold and re-fold the raw billet until the steel became homogenous. The swords created from this form of pattern-welded steel are legendary for their exceptional beauty and quality.
Damascus steel is the ultimate medium for artistic expression in the realm of knifemaking. Not only does the smith build the knife, but he also creates the steel from which it is built. The subject of Damascus steel has filled many books, I recommend that the serious student read anything they can on the subject. In its basic form, Damascus is composed of two or more steels of differing carbon content laminated together by forge-welding. The pattern in the steel is developed through repeated forge-welding to increase the number of layers in the billet, and by manipulating the billet using specific techniques to control and refine the pattern. Once a blade has been made from the billet, it is immersed in acid. The acid etches the different types of steel at different rates, revealing the final layered pattern in the steel.
Mosaic Damascus is a more complicated form of pattern-welded steel. A mosaic is formed by creating a recognizable figure or form in the steel, often seen in the end grain of the billet. Various techniques are used to bring this figure or form to the surface of the steel or to repeat it along the length of the blade.
The possibilities that recent techniques have opened prove the old assertion to be true; the only limits are imagination and skill. Damascus is the next level indeed.
The Damascus steel knife above was made by JWS III Handmade Knives, who has a store on http://www.JustCustomKnives.com.