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:
Intermetallic titanium aluminide alloys are multiphase assemblies with complexmicrostructure and constitution, involving the phases γ(TiAl), α2(Ti3Al), β, and B2. The earlier stagesof phase transformation and dynamic recrystallization occurring upon hot-working of such an alloywere investigated at the atomic scale by high-resolution electron microscopy. Accordingly, theconversion of the microstructure is triggered by heterogeneities in the deformation state andnon-equilibrium phase composition. The β/B2 phase is apparently unstable under tetragonaldistortion, which gives rise to the formation of the B19 phase via distinct shuffle displacements.These processes lead to a modulated microstructure, which is comprised of several stable andmetastable phases. The phase transformations are accomplished by the propagation and coalescenceof ledges. Large and broad ledges can apparently easily be rearranged into intermediate metastablestructures, which serve as precursor for the nucleation of new grains
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/17/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.558-559.465.pdf
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