Fabrication of V-based Laves phase compound multifilamentary wires by applying a rapidly-heating/quenching process to PIT precursors and using a V tube

摘要

We fabricated V-based Laves phase compound such as V_2(Hf,Zr) multifilamentary wire by applying a rapidly-heating/quenching (RHQ) process. Pure Hf and Zr metal powders were mixed and it put in high pure V tube composed with tantalum (Ta), and it was drawn in order to make wire (powder-in-tube (PIT) method). The wires were heat-treated by RHQ process, and some were annealed additionally in vacuum. Since Ta has a higher melting point than V, it is expected that the alloying prevents from breakage of the precursor wire during RHQ treatment because the maximum temperature exceeds 2500 K. SEM observation confirmed that the thick reaction layer within about 10 microns was formed on the boundary of the powder mixture filament and the V matrix after the RHQ. T_c values of the as-quenched samples increased with increasing maximum temperature during RHQ process, and the maximum mid point T_c value was about 8.0 K. The transport J_c properties under magnetic fields were also investigated.