Powder Metallurgy Processes—A Review of the Status and Promise

Abstract

The first demonstration of a superconducting material with a high critical current at high magnetic fields was reported in 1961 by Kunzler et al.¹ for Nb₃Sn. It was produced by a powder process. This development was the first promise of superconducting materials for high field magnet applications. Improved superconducting materials have been developed over the last two decades so that the promise has been partially fulfilled. Although Kunzler’s materials employed a powder process, practical fabrication technologies have favored other fabrication techniques for A15 materials. Recently several powder processing approaches have been developed as alternatives to the now more conventional processes. This review gives source references and brief descriptions of the infiltration, ECN, and hot and cold powder processes. It also outlines some advantages and disadvantages of these processes and indicates the status of their development. In order to assess a process as a viable industrial alternative to existing technologies, factors such as cost of initial materials, fabrication costs, and performance of the final wires are required. This assessment is difficult to make until industrial transfer occurs. However, it is possible to make promises based on apparent advantages over existing processes. This review follows historical precedence.

Invited paper.

Work supported by the U.S. Department of Energy.

Supported by the National Science Foundation.