Techno-Wootz™ Damascus Steel
Hardness is what gives steel its armor-piercing, edge-holding strength. But steel must also be flexible enough to withstand the stress of combat without breaking. In most cases, swordsmiths compromise hardness for flexibility and toughness, or vice versa, to strike a balance between these two properties. It hasn’t always been so. In fact, the ancients forged blades of Damascus steel that provided a sharpness and durability that is legendary even today. The origin and true nature of Damascus steel are still hotly debated among modern smiths and metallurgists. The underlying cause of much of the debate is the difficulty of replicating the properties of Damascus steel. But a technolgical breakthrough at Angel Sword has resulted in the creation of Techno-Wootz™ Damascus steel. So, what exactly is Techno-Wootz™ Damascus steel? First, it helps to define a few terms for those not familiar with metallurgy. Pattern-welded steel – Often referred to as mechanical Damascus, this steel consists of two or more dissimilar irons or steels which are forge welded and then folded or twisted to produce the characteristic Damascus pattern. This represents one of the earliest ways of making steel. Romans employed forge welding in the production of their swords, and Viking swords are well known for the beautiful patterns developed using their forge welding techniques. True Damascus steel - While a number of steels fall under the modern definition, it can be argued that there is only one original Damascus steel. Original Damascus refers to Indo-Persian wootz or bulat steel. Wootz is metallurgically superior to pattern-welded steel. It is not folded, rather it achieves its characteristics through the segregation of a single steel into multiple steels with different carbon contents, crystalline structures and alloy levels. While there are different theories as to why this occurs in true Damascus steel, there is general agreement that it possesses superior hardness and flexibility. Today, Techno-Wootz™ Damascus steel has achieved this same segregation and crystalline structure as true Damascus. Independent verification of the properties of Techno-Wootz™ Damascus steel has been performed by Dr. Eric Taleff, Assistant Professor in the Department of Mechanical Engineering at the University of Texas at Austin. (A .PDF file of his report is available; size 1.53 megs) As with Eastern or Oriental Damascus, the crystalline pattern can be manipulated to produce stunning visual effects in the steel - Celtic knotwork, for instance. And while the visible surface pattern on Techno-Wootz™ Damascus steel is beautiful, the real beauty of this steel is more than skin deep. Techno-Wootz™ Damascus steel has the same unique internal metallurgical microstructure as classic Wootz steel. Picture 1 shows a micrograph of the internal structure of Techno-Wootz™ Damascus, magnified 2000 times. At this resolution, the individual crystals of tempered martensite are visible. The picture also reveals the micro-banding that gives this steel its special properties. Also visible are carbide particles (white spots) embedded in the crystalline matrix. The two superimposed black lines highlight the bright carbide bands at the top and bottom and the dark matrix band between. Picture 2 shows indentations from hardness testing on our Techno-Wootz™ Damascus steel. As shown, the indentations are made both inside and outside the visible banding, revealing a consistent hardness in the matrix. Destruction testing at the Angel Sword shop has shown that Techno-WootzTM Damascus steel is highly resistant to fracture, compression, stress strain, bending and fatigue. Picture 3 shows a cross section of a blade at a magnified 150 times. Visibile banding occurs throughout the steel. Angel Sword produces Techno-Wootz™ Damascus steel in both hypo- and hyper-eutectoid Wootz, with carbon contents ranging from 0.4 percent to 1.6 percent. The bands or sheets of carbides can be produced in either pearlite or martensite matrices and the frequency, or spacing, of the sheeting can be controlled. Techno-Wootz™ Damascus steel can be re-homogenized as described by Verhoeven. Independent verification of the properties of Techno-Wootz™ Damascus steel has been performed by Dr. Eric Taleff, Assistant Professor in the Department of Mechanical Engineering at the University of Texas at Austin. The legendary status of Wootz steel was not based on looks alone. The performance of true, or crystalline, Damascus blades established their reputation. Angel Sword's Techno-Wootz™ Damascus steel represents the latest evolution of this legendary steel. For those desiring more information about wootz Damascus, an informative article by J.D. Verhoeven, A.H. Pendray, and W.E. Dauksch is available online. |
The
heart of every blade is the steel from which it is forged. The basic
ingredients for steel are iron and carbon – but there is much
more to the tale. The amount of carbon and other alloys in a steel blade
affect hardness and flexibility and can be varied according to the skill
and desire of the smith.|
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