Control of Microstructure for Co-Cr-Mo Fibers Fabricated by Unidirectional Solidification

Abstract

Co-Cr-Mo alloy fibers of 2 mm in diameter were fabricated from the melt at 1, 2, and 5 mm/min growth rates by unidirectional solidification using an alloy-micro-pulling-down (A-µ-PD) method to control the microstructure. All elements, Co, Cr, and Mo, were distributed in stripes elongated along the growth direction due to constitutional undercooling. Both Co-Cr-Mo fibers fabricated at 2 and 5 mm/min growth rates were composed of the γ phase with a face-centered cubic structure (fcc-γ phase) and ε-phase with a hexagonal close-packed structure (hcp-ε phase), and the ratio of the fcc-γ phase in the fiber fabricated at 5 mm/min growth rate was higher than that in the fiber fabricated at 2 mm/min. The results suggest that a faster growth rate increases the ratio of the fcc-γ phase in the Co-Cr-Mo fiber fabricated by unidirectional solidification.

Mechanical and Microstructural Characterization of Metals and Alloys

“…Another example of the complex relationship between the desired properties and the process routine can be found in reference [2]. A Co-Cr-Mo alloy can be a good option as a biomaterial because of its excellent mechanical properties, corrosion resistance, and biocompatibility.…”