Nanoprecipitation in a beta-titanium alloy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:623

Article

Coakley, James¹  Vorontsov, Vassili A.¹  Littrell, Kenneth C.²  Heenan, Richard K.³  Ohnuma, Masato⁴  Jones, Nicholas G.⁵  Dye, David¹ 

[1] Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England

[2] Oak Ridge Natl Lab, Chem & Engn Mat Div, Oak Ridge, TN 37831 USA

[3] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England

[4] Hokkaido Univ, Lab Quantum Beam Syst Engn, Sapporo, Hokkaido 0600808, Japan

[5] Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England

关键词: Metals and alloys;    Precipitation;    Transmission Electron Microscopy, TEM;    Neutron scattering;    Titanium alloys;   

DOI  :  10.1016/j.jallcom.2014.10.038

来源: Elsevier

【 摘 要 】

This paper represents the first application of small angle neutron scattering (SANS) to the study of precipitate nucleation and growth in beta-Ti alloys in an attempt to observe both the precipitation process in-situ and to quantify the evolving microstructure that affects mechanical behaviour. TEM suggests that athermal omega can be induced by cold-rolling Gum metal, a beta-Ti alloy. During thermal exposure at 400 degrees C, isothermal omega particles precipitate at a greater rate in cold-rolled material than in the recovered, hot deformed state. SANS modelling is consistent with disc shaped nanoparticles, with length and radius under 6 nm after thermal exposures up to 16 h. Modelling suggests that the nanoprecipitate volume fraction and extent of Nb partitioning to the beta matrix is greater in the cold-rolled material than the extruded. The results show that nucleation and growth of the nanoprecipitates impart strengthening to the alloy. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

Free