Improved niobium 47 weight % titanium composition by iron addition

Abstract

The effect of iron addition on the ductility and superconducting properties of Niobium Titanium alloys has been explored. The conclusion of this study is that iron up to 2000 parts per million by weight is not deleterious to the fabricability of multifilamentary composites. The hardening rate of the iron rich alloy as filaments in a copper matrix was observed to be the same as for low iron versions of the same nominal composition. The development of the pinning microstructure was monitored and compared to the critical current properties of the wire. The results for multifilamentary wires are compared for heats with and without high iron contents. The results were reproduced in the production environment from a full scale ingot. The critical current density for the iron enriched material is elevated relative to the low iron material at high fields. The beneficial influence of iron on the superconducting properties is discussed in light of the microstructure. A designed experiment was conducted to explore the range over which the chemistry can be varied without affecting the behavior. The goal is to broaden the range of iron allowed in Niobium Titanium alloys for superconducting applications.