Nb-Al powder metallurgy processed multifilamentary wire

Powder metallurgy processed Nb-Al wire with overall critical current densities, Jc, at 4.2K up to 10⁴A/cm²at 19T has been investigated in more detail, Kramer plots and directly measured Hc2values of samples with different heat treatments show an increase in Hc2at 4.2K up to 24.5T. Test coils, using long lengths of wire, and tested in fields up to 15T, show Jcvalues equal to those of short samples. Multiple strand hydrostatic small scale extrusions were made. A number of third element additions including B, Mg, Co, Cr and Ni in fine powder form were incorporated in the P/M processing but these did not improve Jc. ac losses were measured and used to determine Jcat 10w fields. The high field ac losses are lower than that for any In Situ or powder processed Nb3Sn wires.