Strength and electrical conductivity of a deformation-processed Cu-5 Pct Nb composite

A Cu-5 pct Nb alloy was deformation processed by wire drawing to very large reductions (99.9993 pct) and the strength and electrical conductivity properties compared with similarly deformation processed Cu-20 pct Nb. The results showed that the Cu-5 pct Nb alloy was transformed into a composite material with the original Nb dendrites becoming ribbonlike filaments in a similar fashion to higher Nb-containing Cu-Nb alloys. The degree of strength increase with increasing deformation processing greatly exceeds rule-of-mixtures expectations at higher degrees of deformation processing, where the Nb becomes highly aligned with the wire axis. A 5 pct Nb addition appears to contain close to the minimum amount of Nb phase necessary to produce appreciable strengthening during deformation processing of Cu-Nb alloys. The strength-conductivity properties of the deformation-processed Cu-5 pct Nb alloy show significant improvements in strength over the best commercial alloys in the conductivity range of 80 to 90 pct international annealed copper standard (IACS). This article is based on a presentation made in the symposium “High Performance Copper-Base Materials” as part of the 1991 TMS Annual Meeting, February 17–21, 1991, New Orleans, LA, under the auspices of the TMS Structural Materials Committee.