Role of oxygen on the precipitation and deformation behavior of an aged β Ti-15Mo alloy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:891

Article

Chou, Kathleen^1,2  Marquis, Emmanuelle A.¹ 

[1] Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA

[2] Eaton Corp, Southfield, MI 48076 USA

关键词: Metals and alloys;    Phase transitions;    Precipitation;    Microstructure;    Mechanical properties;    Titanium;   

DOI  :  10.1016/j.jallcom.2021.161811

来源: Elsevier

【 摘 要 】

The mechanical behavior of aged metastable beta titanium alloys is directly influenced by the formation and stability of metastable omega and stable alpha phases during thermomechanical processing. Interstitial oxygen, which is known to cause embrittlement in Ti alloys, affects phase stability in these alloys and also impacts their structural properties. The present study investigated the role of interstitial oxygen on omega and alpha precipitation in an aged metastable beta Ti-15Mo alloy and the subsequent effect of these microstructural changes on the alloy's compressive mechanical properties. High oxygen levels reduced the omega growth rate and induced a shape change for omega precipitates with oxygen partitioning to omega precipitates during ageing. Oxygen containing specimens displayed higher compressive yield strengths than in oxygen-free specimens during micropillar compression testing. However, in both cases, omega precipitates were ultimately sheared leading to slip band formation and plastic flow localization. Elevated oxygen also refined the alpha precipitate distribution whether alpha nucleation happened homogeneously or heterogeneously. The finer alpha precipitates with oxygen led to increased compressive yield strength during micropillar compression compared to specimens without oxygen. Oxygen plays a key role in the evolution of omega and alpha precipitate distributions and associated mechanical properties, which is another example of how oxygen may be a useful alloying element in beta titanium alloys. (c) 2021 Published by Elsevier B.V.

【 授权许可】

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