Observations of Room Temperature Creep Recovery in Titanium Alloys

Published

March 1, 2002

Author(s)

M Savage, T Neeraj, M J. Mills

Abstract

Conventional α (hcp) and α (hcp)/Β (bcc) titanium alloys exhibit significant primary creep strains at room temperature and at stresses well below their macroscopic yield strength. It has been previously reported that repeated unloading during primary creep testing may either accelerate or retard the accumulation of creep strains. These effects have been demonstrated to depend on both microstructure and the applied stress. This article demonstrates that significant room-temperature recovery occurs in technologically relevant titanium alloys. These recovery mechanisms are manifested as a dramatic increase in creep rates (by several orders of magnitude) upon the introduction of individual uploading events, ranging from 1 minute to 365 days, during primary creep tests. Significant increases in both creep rate and the total accumulated creep strain were observed in polycrystalline single α -phase Ti-6Al, polycrystalline α/ Β Ti-6Al-2Mo-0. 1Si, and individual α/Β colonies of Ti-6242. Based on transmission electron microscopy (TEM) studies of the active deformation mechanisms, it is proposed that the presence of significant stress concentrations within the α phase of these materials, in the form of dislocation pileups, is a prerequisite for significant room-temperature recovery.

Citation

Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science

Volume

33A

Pub Type

Journals

Keywords

creep behavior, room temp recovery, titanium alloys

Citation

Savage, M. , Neeraj, T. and Mills, M. (2002), Observations of Room Temperature Creep Recovery in Titanium Alloys, Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science (Accessed July 27, 2024)