Nickel-refractory metal substrate tapes with high cube texture stability

The effect of different impurity levels in nickel on the quality of the primary recrystallization cube texture after intense cold rolling was investigated. Texture sharpness and thermal stability in the 99.9 at% nickel tapes could be improved by micro-alloying with molybdenum and tungsten as well as with niobium and tantalum. Furthermore, micro-alloying reduced the susceptibility of the substrate materials against grain boundary grooving at processing temperatures in the range of about 800 °C. Highly alloyed nickel with 5 at% tungsten was not susceptible to thermal etching effects independent of the processing route, i.e. melting or powder metallurgy. Cube textures were obtained for different nickel-refractory metal alloys with characteristic in-plane orientations of FWHM: 4-8°. The performance of this group of substrate materials for coating with ceramic buffer and superconductor layers could be proven by the achieved maximum critical current density of 1.2 MA cm-2 at liquid nitrogen temperature and zero magnetic field.