Work

Observation of α phase nucleation within ω precipitates with novel orientation relationship in a low misfit metastable β-Ti alloy through EBSD

Year: 2024

Type: article

Abstract: During isothermal ageing of metastable β-Ti alloys decomposition of the β matrix occurs through the formation of either the ω or α phases . Recent literature has shown that the presence of ω iso can facilitate α nucleation forming an α variant with a known orientation relationship to the β and ω phases. However, the mechanisms behind such a transformation are unclear, especially in systems with a low ω-β misfit. In this study, the effect of 450 °C ageing on a low misfit alloy, Ti-26Nb (at.%), has been studied using electron backscattered diffraction (EBSD). Isothermal ω precipitates were observed to coalesce along preferred growth directions. EBSD identified the presence of α within the core of the coalesced ω precipitates. The relationship between this α and the parent β was inconsistent with the expected Burgers orientation relationship and did not follow any known crystallographic relationship between α and ω, suggesting a novel transformation pathway.

Source: Scripta Materialia

DOI: 10.1016/j.scriptamat.2024.116335

Authors: CEP Talbot, NL Church, NG Jones

Institution: University of Cambridge

Language: English

Topic: Titanium Alloys Microstructure and Properties

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,220

Funders: Rolls-Royce, Engineering and Physical Sciences Research Council