Fabrication of Metallic Fibers with High Melting Point and Poor Workability by Unidirectional Solidification

Innovative method acceptable for production of Iridium (Ir) and Ruthenium (Ru) metal fibers with high melting point and poor workability is developed using an alloy‐micro‐pulling‐down (A‐μ‐PD) method and ceramic crucibles with sufficient mechanical and thermal shock resistance. As‐grown (as‐solidified) Ir and Ru fibers are approximately 1 mm in diameter and their lengths exceed 15 and 0.3 m, respectively. Both Ir and Ru fibers are composed of number of elongated grains oriented along a growth direction, which is attributable to the unidirectional solidification. The flexibility and oxidation resistance of the Ir fiber grown by the A‐μ‐PD method is considerably improved as compared to a commercial Ir wire made by wire‐drawing process.