Requirements of a dieless wire drawing system

Dieless wire drawing involves the initiation of a localized plastic zone within a constantly tensioned wire. The heat affected zone experiences a temporary reduction in its flow stress. A uniform reduction in cross-sectional area can be initiated by controlling the stability within this region. In-line cooling and subsequent tempering devices enable this continuous process to produce a net finished product with one pass. However, process instability has always been the key identifiable reason for its commercial failure. Recent innovations in data acquisition and motion control have led to a renewed interest in this novel process. This paper outlines the concepts that need to be considered when designing, manufacturing and instrumenting a continuous dieless wire drawing system with flow stability as the primary consideration. Deliberation is given to process parameters and using a kinematic analysis; the key control variables are identified.