Insulation for superconductors

The process of forming a superconducting article comprising a matrix core containing a superconductor, a pure metallic stabilizer layer disposed about said core, and an insulating layer surrounding said stabilizer layer which comprises the steps of providing a superconductor billet in a stabilizer can protected by a diffusion barrier between the superconductor billet and the stabilizer can, surrounding the stabilizer can with an insulating refractory metal (including alloys thereof) which is unreactive with the stabilizer metal at 700.degree. C. and is not superconducting at magnetic fields above 1 Tesla and at a temperature of 4.2.degree. K., providing at least two additional metal layers outside said refractory metal layer to aid in wire drawing, the inner of said two additional layers comprising iron and the outer of said layers comprising copper, coreducing said layers to metallurgically bond said layers, removing said additional copper layer and further reducing said layers to a total reduction by a factor of at least 100 to create a final insulating refractory metal layer less than 20 .mu.m thick and removing said iron layer.