Densification Behavior of BSCCO-2212 Superconducting Powder During the Wire Drawing of Powder-in-Tube (PIT) Samples

There is growing interest in the fabrication of long lengths of defect-free superconducting wires with requisite electrical properties. Numerous techniques and simulations to address processing problems have been reported. The powder-in-tube (PIT) technique has been widely accepted as a viable process for the manufacture of long lengths of superconducting wire. In this work, numerical and experimental analyses were conducted on wire drawing of PIT samples to determine the effect of processing conditions on the densification of BSCCO-2212 powder. Two different die sets and two different silver/oxide ratios were used in the computer simulations and the experiments. The Modified Drucker-Prager material model, based on a cap-type pressure dependent constitutive theory, was used to represent the powder behavior. The finite element model also incorporated experimentally determined material data for both the silver and the powder. The experimental and computer simulation results are discussed to provide a better understanding of the powder behavior and to facilitate process optimization.