Microstructure of CO₂ Laser Beam Irradiated Nb₃Al Superconductor

Abstract

A-15 Nb₃Al tape superconductor has been prepared by high power density and continuous wave CO₂ laser beam irradiation onto moving Nb-Al composite tapes made by the powder method. The irradiated area was melted and then immediately resolidified, which resulted in a fine dendritic microstructure consisting of Nb dendrites embedded in Nb₃Al matrix. Nb₂Al phase was also observed in the heat-affected zone nearby the melted area by laser beam irradiation.