Kabushiki Kaisha Kobe Seiko Sho

Toshiro Fukutsuka

Takao Fujikawa

Masato Moritoki

Norio Gennai

A method of producing compound-type superconducting wires which are dense and free of voids. The method comprises the step of holding a compound-type superconducting wire having voids in an atmosphere of sufficiently high temperature high pressure gas to collapse the voids and weld the collapsed areas, thereby forming a dense, void-free superconducting wire.

Method of producing compound-type superconducting wires

The specification describes a method for producing compound-type superconducting wire of excellent mechanical and electrical properties. A green compact is first formed with copper powder and one of two metals which form a superconducting compound through a reaction therebetween. The latter metal is in a very fine hydrogenated form. The green compact is then heated in vacuo so as to dehydrogenate the hydride of the latter metal and sinter the green compact into a sintered mass. Before or after drawing the sintered mass into a wire, it is composited with the other metal of the two metals, thereby forming a composite wire. It is then subjected to a further heat treatment to cause the reaction to occur between the two metals. To improve its properties, it may be held in a high temperature, high pressure gaseous atmosphere to cause plastic deformation to occur. Since the dehydrogenation and annealing are performed in a single step, the overall process has been simplified. Since the latter metal is dispersed uniformly in the form of highly pure and ultra-fine particles in the Cu-matrix of the sintered mass, it can be drawn very smoothly into a wire and the reaction between the two metals can occur easily. The two metals may for example be Nb and Sn or V and Ga.

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Kobe, Japan

Toshiro Fukutsuka