It is generally known that materials with hexagonally close-packed lattice structures, such as magnesium and zinc-based alloys, have a rather low formability at room temperature. Due to their biodegradable properties, these materials are nevertheless in the focus of interest for numerous medical applications, especially in the form of thin wires. In this context, the formability and processability are one of the most important factors in the production of wires.
Manufacturing wires is commonly realized by applying a conventional multiple pass cold wire drawing process. To achieve better processability by using hot forming and to obtain higher diameter reductions per pass, the innovative dieless wire drawing process is presented in this study. In the dieless drawing process, the wire is heated locally and the thinning of the wire takes place in a localized plastic deformation zone under an external tensile load. With an adjustable drawing force, the process can achieve large diameter reductions in a single pass, making it a more efficient hot manufacturing process for magnesium-based thin wires.
In order to investigate the processability during the dieless wire drawing process for magnesium-based wires, a selection of magnesium- and, for comparability, zinc-alloys as well as process parameters were chosen and wire manufacturing was carried out using a multiple pass dieless drawing process route. The process parameters drawing speed, feeding speed and temperature are analyzed and the resulting process windows for the selected materials are discussed.