Folding (forging process)
The wrinkle is one of the main forging techniques in the field of knife and sword-making. The blank is heated, stretched with a blacksmith's hammer, partly split, folded over at the broken edge and forged back together with a hammer.
A traditional Japanese katana , for example, has exactly 32768 layers in the cutting edge after only 15 folds. As a result, any additives such as carbon are not only optimally distributed in the blank, but also micro-fractures that previously existed in the blank are almost completely eliminated.
The specialty of forging is that you can create alloys in a purely mechanical way with relatively little effort, the mixtures of which consist of a constant composition down to the individual atomic layers.
Theoretically, almost any macroscopic structure down to the molecular level can be transferred or reproduced with it, so the blank can also be twisted by forging or knotted with a woven structure before folding. With every fold, this original structure is reduced by half - with possibly completely new material properties in the end product.
See also
- Damascus steel
- Sponge iron , luppe (metallurgy) (also race iron )
- Racing furnace
- Knife steel