Pattern Welded Damascus Steel
(Some ofWhat I Have Learned So Far)
1. The idea.
What is pattern welded damascus steel ? The basic concept is very simple, and can be expressed by thinking about plywood as opposed to solid wood. The plywood is comprised of layers of thin materials laminated together. This is sort of what pattern welded steel is like also. It is composed of many layers of at least two varieties of steel (usually two, more certainly is not a problem). When the resultant bar is then forged to shape, either directly into the shape of a knife, or to a bar size, the layers are distorted, thus causing them to no longer be simply parallel sheets. Then, when the blade is ground to it's final geometry, the layers are cut through, and a pattern emerges. At this point, depending on several variables such as steel choices and the microstructure of the blade, the pattern may or may not be as visible as one would like. The finishing process is very important to the appearance of the finished blade, and amounts to polishing, and then etching with some sort of oxidizing chemical to bring the pattern out so that it is readily apparent. By choosing alloying elements in the component materials, ands altering the finish of the surfaceand the etch, the appearance can be anything from very subtle to very bold. The background of this page is a section of a "random" pattern blade. The reason it is called "random" is that there was no deliberate, specific manipulation of the bar as the blade was forged to shape to create a particualr pattern in the steel. The pattern here is the result of simply forging the blade to the shape of the knife with a hammer.
2. Pattern manipulation
There is literally no end to the variety of patterns obtainable with these materials. Whatever one can imagine, can be put into a bar of steel if the smith is willing to spend the time to do so. I have seen examples of very controlled mosaic patterns like Daryl Meier's American flag of a few years back, and Steve Schwarzer's hunting scene, complete with a man holding a shotgun, dogs, and a rising covey of quail. I have done some simpler geometric mosaic myself, and still other smiths have done a great deal of cool steel with a strong element of "randomness" or "maximum distortion" as one of my buddies (Al Dippold) puts it.
The basic repertoire of pattern welded steel starts with a layered bar of more or less parallel sheets of at least two varieties of steel. This bar can be manipulated by several basic operations to achieve a nice stable of patterns without killing one's self on mosaic or a lot of real expensive equipment. The most familiar deliberate patterns are ladder and twist.
To make a ladder pattern, the layered bar is either cut into at regular intervals across the width of the bar, then forged out flat again, or alternatively, the bar can be forged into a die set to raise bumps across the width of the bar, and then the resultant bumps or ridges ground off afterward. The former is easier to learn, the latter the more precise for layout and spacing of the "rungs" of the ladder. They appear very similar in the end, and I do not think one or the other is better or worse, personally.
Twist pattern is sort of self-explanatory. The bar is made to be square to round in section, then heated and twisted, then forged flat again. I normally forge the bar to an octagonal section, not square, and not exactly round either, if I am going to do a simple single bar twist. Do the twisting at welding heat, or nearly so to minimize the chances of the bar coming from together to apart. Twisting put a huge amount of stress on all of the forge welds, and if they are not good, you will find out rapidly when you apply roatational torque to the bar. If a twisting apparatus is not available to you, then I suggest having an assistant if possible. Four hands are better than two, especially if the bar is large in section or length or both.
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