High Frequency Vibrations Impact on Mechanical Properties of Nanocrystalline Titanium
S. А. Bakai$^{1}$, R. V. Smolianets$^{2}$, K. V. Kovtun$^{1}$, V. А. Moskalenko$^{2}$, A. S. Bakai$^{1}$
$^{1}$National Science Center Kharkov Institute of Physics and Technology, NAS of Ukraine, 1, Akademicheskaya Str., 61108 Kharkov, Ukraine
$^{2}$B.I. Verkin Institute for Low Temperature Physics and Engineering, NAS of Ukraine, 47 Nauky Ave., 61103 Kharkiv, Ukraine
Received: 07.12.2015. Download: PDF
Mechanical properties of nanocrystalline titanium are studied under uniform confined compression with ultrasound oscillations of 20 kHz to clarify the way of high-frequency vibrations’ effect on mechanical properties of nanocrystals. The nanocrystalline VT1-0 titanium of commercial purity used in the experiments is fabricated employing cryogenic grain-fragmentation technique. This material has a broad distribution in grain size (20—80 nm) with the average size amounting to 40 nm. The amplitude of cyclic stress approaches 275 МРа. The high-frequency vibrations are found to lower the yield stress and to initiate the formation of shear bands. With the deformation rate of 10$^{-4}$ s$^{-1}$, the yield stress becomes 2.5 times lower, and the major shear band forms under the deformation of 0.11 that is 5.7 times lower than the true deformation before the major shear band formation without action of the vibrations. On increasing the deformation rate up to 10$^{-3}$ s$^{-1}$, the consequences of high-frequency vibrations’ impact are weaken substantially.
Key words: nanoscale titanium, mechanical properties, strength, ductility, high-frequency vibrations.
URL: http://mfint.imp.kiev.ua/en/abstract/v38/i02/0189.html
DOI: https://doi.org/10.15407/mfint.38.02.0189
PACS: 62.20.fg, 62.20.me, 62.25.Fg, 62.25.Mn, 81.40.Jj, 81.40.Np, 81.70.Cv
Citation: S. А. Bakai, R. V. Smolianets, K. V. Kovtun, V. А. Moskalenko, and A. S. Bakai, High Frequency Vibrations Impact on Mechanical Properties of Nanocrystalline Titanium, Metallofiz. Noveishie Tekhnol., 38, No. 2: 189—203 (2016)