Scientific Reports (Oct 2024)

Chemical origins of β-Ti stabilization via B4C additions in metastable β-Ti alloys and composites

  • Vitor V. Rielli,
  • Rodrigo J. Contieri,
  • Sophie Primig

DOI
https://doi.org/10.1038/s41598-024-76207-1
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 10

Abstract

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Abstract The aerospace industry relies on Ti alloys owing to their strength-to-weight ratio and corrosion resistance. In metastable β-Ti alloys, slow cooling from the β-transus leads to partial transformation into coarse α laths, which is detrimental to the mechanical properties. A refinement and decrease of α laths has been previously achieved in β-Ti alloys with B4C additions. In these materials, the ductility of β-Ti is preserved, and the TiB and TiC particles promote strengthening. However, the mechanism of the β-Ti stabilization remains unclear. Using atom probe tomography, we propose that Mo enrichment in the α-phase limits its growth by reducing the influx of Al from the β-phase. The complex chemical environment near eutectic TiB is enriched in Al and TiO, promoting heterogeneous nucleation of fine α-phase. Increased TiO concentration is observed with the introduction of B4C. A fundamental understanding of the α-refinement mechanism in Ti-alloys is critical for aerospace applications demanding high performance and reliability.

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