Development of Composite RABiTS Tapes for Coated Conductors

Substrate materials are the key element of the coated conductors. There are two types of substrates-nontextured (stainless steel (SS) or Hastelloy alloys) and textured ones which are based on the Ni-W alloys. The main requirements for the textured tapes (RABiTS) are the presence of the highly pronounced biaxial cubic texture {100} <;100> and low values of magnetic susceptibility. To realize these requirements RABiTS tapes of various kinds were developed-homogenous tapes from Ni-W alloys with W content 5.5-9 at.% and composite ones. Composite tapes consist of three layers-one of SS and two of Ni-W alloy with W content 6 at.%. Mechanical and magnetic properties of the tapes were investigated and the dependence of tapes texture quality from total accumulated deformations was studied. The ultimate tensile strength value of composite tapes was 750± 10 MPa. The conditions necessary to form the required {100} <;100> texture are different for the homogeneous and composite tapes. According to the magnetic measurements saturation magnetization of composite tapes is about a factor of two lower than for similar homogeneous tapes.