-What is Damascus?-
'Damascus steel,' as we usually call it, can be made from almost any
steel and a few other materials as well. What we now call 'damascus,'
is more properly referred to as 'pattern welding'. The use of the word
'damascus,' in this context is a misnomer dating back to a very early
European misunderstanding. True 'damascus,' is believed to refer to a
material called 'wootz,' made in India and first seen by Europeans
during the Crusades in the city of Damascus. Wootz steel is the result
of a particular alloy and smelting process that creates a material with
differing crystalline structures (cementite in a pearlite matrix,) that
become visible when etched. The confusion between the two arose
because 'pattern-welding,' also has a characteristic surface pattern
that pervades the actual structure of the blade, though they are easily
separated by the educated eye.
The Northern European Dark Ages marked the height of more than a few crafts, and pattern welding is included in this often overlooked era of master artisans. From the Migration Era following the fall of Rome to the establishment of Charlemagne's Empire the pattern welded blade reigned supreme. Typically these blades made use of high and low carbon steels to acheive a blade that was strong and resilient. They often had a core of soft low-carbon pattern welding with hardened high carbon edges, making the best of the capabilities of both materials; and conserving the valuable high carbon material.
Although the pattern welded blade has its advantages, technological advancements made homogenous plain carbon blades somewhat better and vastly easier to produce at the onset of the Medieval Age. It has not been until recently that newer steels and artistic endeavor have brought the craft of pattern welding back to prominence. The availability of highly complex and consistent steels allows for far greater aesthetic and functional expression than ever before. Even non-ferrous metals can be worked into Damascus given today's clean materials and technology.
A love of history inclines me to focus on traditional twists, ladders and composite constructions. The smiths of the Dark Ages developed complex composite constructions to maximize their materials and create aesthetically beautiful blades. All of my blades are generally made with 1084 and 15N20. These steels provide a nice contrast, forge well and are very responsive to heat treating.
This is a billet bound and ready to be forge-welded together.
After one end is welded the binding wire is removed.
The billet is placed into the forge until red-hot. It is then be removed and coated with borax, which acts as a flux. A flux prevents oxygen from reacting with the metal, a process accelerated by heat resulting in iron oxide, or 'scale'. This scale would inhibit fusion of the layers and create inclusions in-between the layers that would be revealed during grinding. Other materials can work as flux but borax not only absorbs oxygen, it also absorbs small amounts of scale and creates a chemically clean surface for the welding.
I wear a face shield and heavy leather when welding. Usually.
I used do most of my forge-welding on a foot-powered treadle hammer. Then
I got a hydraulic press. It saves me hours and hours of hard work. The
blade is heated to red, coated in borax and placed back in the forge
until white-hot. It is then immediately placed under the hammer and
struck with the force of several hundred pounds. When done properly
this fuses the layers forever together.
I use a variety of dies in the hammer- I have 5" x 5" flat plates for flattening and squaring; 2" x 3" slightly domed plates for welding and 2" x 1" x 1" rounded fullers for stretching out. A slight radius hits the center of the billet first and help to push out flux and scale, whereas the flat plates often trap material in the center of the billet. It seems to be less of an issue in the hydraulic press.
Now the process is to stretch the billet out and fold upon itself until the desired number of layers is achieved. Of prime importance is keeping the sides to be joined absolutely flat ( or slightly thinner toward the edge,) and -very- clear of scale. I lightly grind between welds, mainly to get rid of nickel oxides from the 15N20.
I average about one fold an hour on the treadle hammer and probably two to three on the press. Twelveoriginal layers become 24, then become 48 etc. It only takes six courses of welding, drawing out and folding to achieve approximately 300 layers. ( Some are lost to oxidation & grinding.) I can get three smaller blades with full-tangs out of one billet. A large bowie, sax or sword might take up several.