ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The thermal stability of equal channel angular extruded VT-6(Ti-6Al-4V) has beenexamined using micro-hardness, nano-hardness of the individual αand β phases backscatteredscanning (BSEI) and transmission electron microscopy (TEM). After straining to an equivalent totalequivalent of 6.5 samples were annealed for 1 h at temperatures between 175 and 800 o C followedby water quenching. Micro and nano-hardness measurements showed an initial hardness increase,the former rising to a maximum at 175ºC, while the latter exhibited a maximum at 500ºC. BSEI andTEM analysis showed that these observations can be understood by considering the microstructurechanges occurring at different length scales. Annealing in the temperature range of 175 to 500°Cdid not significantly alter the α and β particle size, while TEM showed that recovery andcontinuous recrystallization occurred in the α phase, higher temperatures being required to activatethe recovery and recrystallization processes within the β phase. Finally at temperatures above 600ºCspheroidization and growth of the β phase occurred with the volume fraction of this phaseincreasing from 15 pct at lower temperature to 25 pct at 800ºC, an equi-axed α+ β microstructurebeing observed at this temperature
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.893.pdf
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