The α–ω phase transition in shock-loaded titanium

Journal Article · Fri Jul 28 00:00:00 EDT 2017 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4987146· OSTI ID:1374352

Jones, David R. ^[1]; Morrow, Benjamin M.  ^[1]; Trujillo, Carl P. ^[1]; Gray, George T.  ^[1]; Cerreta, Ellen K. ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Here, we present a series of experiments probing the martensitic α–ω (hexagonal close-packed to simple hexagonal) transition in titanium under shock-loading to peak stresses around 15 GPa. Gas-gun plate impact techniques were used to locate the α–ω transition stress with a laser-based velocimetry diagnostic. A change in the shock-wave profile at 10.1 GPa suggests the transition begins at this stress. A second experiment shock-loaded and then soft-recovered a similar titanium sample. We then analyzed this recovered material with electron-backscatter diffraction methods, revealing on average approximately 65% retained ω phase. Furthermore, based on careful analysis of the microstructure, we propose that the titanium never reached a full ω state, and that there was no observed phase-reversion from ω to α. Texture analysis suggests that any α titanium found in the recovered sample is the original α. The data show that both the α and ω phases are stable and can coexist even though the shock-wave presents as steady-state, at these stresses.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1374352
• Alternate ID(s): OSTI ID: 1372949
• Report Number(s): LA-UR-17-22453
• Journal Information: Journal of Applied Physics, Vol. 122, Issue 4; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Titanium
Shock Loading
Phase Transition