Novel drawing technology for high area reduction manufacturing of ultra-thin brass wires

Abstract

A significant increase in roughness of dieless-drawn wires due to the strain-induced roughness phenomenon has been documented. For small-diameter wires, even a slight surface relief creates stress concentrations that may contribute to the wire breakage during cold drawing. This, in turn, significantly limits the achievable diameter of the product and the efficiency of drawing process. The present study, however, demonstrates that reducing the wire roughness is possible by combining the dieless and conventional drawing methods. Thus, it is possible to improve the process workability threefold when compared to dieless drawing alone, and the product quality is simultaneously improved. In addition, the surface defects typical to the dieless-drawn wires have been significantly reduced, resulting in an increase in the wire strength. This new combined technology enables a significant reduction in the wire diameter and facilitates an economical large-scale production of ultra-thin wires. In addition, based on the classic drawing and dieless drawing process, a brass wire with a diameter of 0.017 mm has been manufactured. Six times thinner than a human hair, it is believed to be the thinnest long brass wire currently manufactured in the world.