Journal ArticleDOI
Effect of rapid solidification and alloying addition on lattice distortion and atomic ordering in L1 0 tial alloys and their ternary alloys
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In this article, the lattice parameters of binary and ternary L10 type titanium alloys were studied by X-ray diffractometer using the foils and their powders.Abstract:
Binary and ternary L10 type titanium alloys were rapidly quenched into thin foils by the hammer-anvil quenching technique. The nominal alloy compositions include Ti1-xAlx and (Ti1-xAlx)100-@#@ yMy, wherex = 0.5 to 0.6; y= 1 to 4; and M is V, Cr, Mn, Fe, Co, Ni, and Ge. Lattice parameters of Ll0 phases in these alloys were studied by X-ray diffractometer using the foils and their powders. Simultaneously, long-range order parameters of these Ll0 phases in the as-quenched foils and the annealed powders were determined from the superlattice intensity measured by X-ray diffractometer. Rapid quenching suppresses long-range ordering (S) during solidification and, thereby, reduces lattice distortion (c/a) in Ll0 titanium alloys. A small amount of alloying element has a large effect on thec/a ratio. The atomic size effect and probably substitutional site preference play an important role in such ac/a reduction. From the density measurement, it is found that antisite defects are a predominant mode in Al-rich off-stoichiometric TiAl compound alloys. Determined long-range order value is significantly low in as-quenched binary TiAl due to rapid quenching, and the highest ordering occurs at as-quenched Ti45Al55 alloy. The relationship betweenc/a andS in Ll0 Ti45Al55 may be written asc/a = 1 + 0.025 ·S.read more
Citations
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Journal ArticleDOI
High-temperature strength and fracture toughness in γ-phase titanium aluminides
TL;DR: In this article, the effects of chromium on these mechanical properties were investigated, and it was found that the addition significantly improved the room and high-temperature strength and toughness of binary and chromium-alloyed titanium aluminides.
Journal ArticleDOI
Effect of wheel speed on the microstructure and nanohardness of rapidly solidified Ti–48Al–2Cr alloy
TL;DR: In this paper, the microstructure and nanohardness of rapidly solidified Ti-48Al-2Cr (at%) alloy at different wheel speeds were experimentally investigated by using the single roller melt-spinning technique.
Journal ArticleDOI
First-principles study on structural, elastic and thermal properties of γ-TiAl and α2-Ti3Al phases in TiAl-based alloy under high pressure
TL;DR: In this article, the structural, elastic and thermal properties of α2-Ti3Al and γ-TiAl under pressure were reported using CASTEP program based on the density functional theory.
Book ChapterDOI
4 – Titanium aluminides
R.K. Gupta,B. Pant +1 more
TL;DR: In this paper, a desirable combination of room temperature fracture toughness, high temperature strength, and oxidation resistance is possible to obtain in case of the Moss-Mo3Si-Mo5SiB2 composites.
Journal ArticleDOI
Tracer-diffusion of 44Ti in TiAl single crystal
TL;DR: In this article, the diffusion coefficient of 44 Ti has been measured in the directions parallel to [001] axis and perpendicular to [1] axis, and has been found to be anisotropic; the diffusivity in the direction parallel to the [ 1] axis is an order of magnitude lower than that perpendicular to the 1) axis.
References
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Journal ArticleDOI
X. Quantitative measurement of preferred orientation in rolled uranium bars
TL;DR: In this article, the preferred orientation of uranium bars in the α range was determined by x-ray diffraction using a Geiger counter, and it was shown that hot rolling with a slight reduction causes the 010 planes to become strongly and the 110 planes weakly oriented perpendicular to the rolling direction.
Journal ArticleDOI
Binary phase diagrams
TL;DR: In this paper, the juxtaposition of two binary eutectic diagrams should produce a liquidus with a slope of zero at the melting point of the congruently melting compound.
Journal ArticleDOI
The deformation and fracture of TiAl at elevated temperatures
TL;DR: In this paper, the tensile properties of the intermetallic compound TiAl have been determined at several temperatures in the range 25 to 1000°C, and the results indicate that the ductilebrittle transition behavior of TiAl at about 700°C is controlled by the trailinga/6 [112] partial dislocation components of the superdislocations overcoming their pinning barriers.
Journal ArticleDOI
Positive temperature dependence of the yield stress in TiAl L10 type superlattice intermetallic compound single crystals at 293–1273 K
TL;DR: In this paper, a floating zone method was used to obtain the fundamental knowledge on the plasticity of TiAl single crystals with five orientations and the yield stresses of all orientations tested show a positive temperature dependence similarly to most Ll2 type superlattice intermetallic compounds.
Journal ArticleDOI
The plastic deformation of TiAl
TL;DR: In this paper, the deformation substructure of TiAl (Llo type ordered lattice) was tested in compression, and the factors determining it were investigated, and equi-Schmid factor lines have been constructed in an attempt to evaluate the importance of the sense of the applied stress on the deformability of the alloy.