Ordered intermetallic alloys, part I: Nickel and iron aluminides

JOM ◽  
1993 ◽  
Vol 45 (5) ◽  
pp. 38-44 ◽  
Author(s):  
C. T. Liu ◽  
K. S. Kumar
Keyword(s):  
Iron Aluminides ◽  
Intermetallic Alloys ◽  
Ordered Intermetallic

Bonding and stability in the ordered alloys FeV and CoTi. Comparison with FeTi

1985 ◽  
Vol 50 (10) ◽  
pp. 2093-2100
Author(s):  
Štěpán Pick ◽  
Mojmír Tomášek ◽  
Mojmír Šob
Keyword(s):  
Phase Diagrams ◽  
Partial Wave ◽  
Partial Wave Analysis ◽  
Intermetallic Alloys ◽  
Wave Analysis ◽  
Ordered Alloys ◽  
Ordered Intermetallic ◽  
Cscl Structure ◽  
Ionic Effects

Partial wave analysis together with the qualitative examination of hybridization has been performed for two ordered intermetallic alloys with CsCl structure, FeV, and CoTi. The results resemble those obtained previously for FeTi, although important deviations are present as well. The stabilization of the ordered phase is again due to ionic effects. Qualitative arguments are suggested to explain the small stability of the CsCl phase of FeV and some differences in the FeTi and CoTi phase diagrams.

Atomistic Computer Modeling of Intermetallic Alloys

2005 ◽  
Vol 502 ◽  
pp. 21-26 ◽  
Author(s):  
Yuri M. Mishin
Keyword(s):  
Computer Modeling ◽  
Atomic Diffusion ◽  
Intermetallic Alloys ◽  
Empirical Potentials ◽  
Atomic Interactions ◽  
Ordered Intermetallic ◽  
Interphase Boundaries ◽  
Dislocation Behavior ◽  
Semi Empirical ◽  
Expansion Point

The paper gives a brief overview of our recent work on atomistic computer modeling of ordered intermetallic compounds of the Ni-Al and Ti-Al systems. Atomic interactions in these systems are modeled by semi-empirical potentials fit to experimental and first-principles data. The methodology includes a large variety of techniques ranging from harmonic lattice dynamics to molecular dynamics and Monte Carlo simulations. The properties studied include lattice characteristics (elastic constants, phonons, thermal expansion), point-defect properties, atomic diffusion, generalized stacking faults, dislocations, surfaces, grain boundaries, interphase boundaries, and phase diagrams. We especially emphasize the recent progress in the understanding of diffusion mechanisms in NiAl and TiAl, calculation of stacking fault energies in Ni3Al in relation to dislocation behavior, and calculations of / 0 interface boundaries in Ni-Al alloys.

Investigation of B2 and Related Phases in Ti-Modified Nb-Al Alloys

1993 ◽  
Vol 322 ◽  
Author(s):  
D.-H. Hou ◽  
S.S. Yang ◽  
J. Shyue ◽  
H.L. Fraser
Keyword(s):  
Site Occupancy ◽  
Orthorhombic Phase ◽  
Intermetallic Alloys ◽  
Heat Treated ◽  
Three Phase ◽  
Ordered Intermetallic ◽  
Tie Lines ◽  
Second Phases ◽  
A15 Phase ◽  
O Phase

AbstractThe B2 ordering and phase stability of three ordered intermetallic alloys with compositions (in at.%) of Nb-15Al-10Ti (10Ti alloy), Nb-15A1-40Ti (40Ti alloy), and Nb-15Al-25Ti (25Ti alloy) have been studied. All three alloys have the B2 crystal structure in the as-cast form. The Atom Location by Channeling Enhanced Microanalysis (ALCHEMI) technique has been employed to assess the site occupancy of these B2 alloys. The results of site occupancy are represented as Ordering Tie Lines on a ternary composition diagram. Various second phases were observed in heat treated samples. An ω-type phase was found in the 1OTi alloy in samples heat treated for 10 minutes and 4 hours at 900°C. At 800°C, orthorhombic phase was found in the 40Ti alloy while a three phase microstructure of o-phase/B2/A15 was observed in both the 10Ti and 25Ti alloys. Annealing at 1100°C leads to the dissolution of the o-phase and the presence of A15 phase in the 10Ti and 25Ti alloys, but no other phase in the 40Ti alloy. The observed phase equilibria in these alloys are compared with those in the literature.

Micromechanisms of yield and flow in ordered intermetallic alloys

1988 ◽  
Vol 36 (11) ◽  
pp. 2935-2946 ◽  
Author(s):  
M.H. Yoo ◽  
J.A. Horton ◽  
C.T. Liu
Keyword(s):  
Intermetallic Alloys ◽  
Ordered Intermetallic

STUDY ON THE PEIREL–NABARRO STRESS OF IRON ALUMINIDES

2012 ◽  
Vol 19 (06) ◽  
pp. 1250057 ◽  
Author(s):  
L. X. PANG ◽  
N. F. HAN ◽  
H. SHI ◽  
J. XU ◽  
X. H. HAO ◽  
...  
Keyword(s):  
Domain Boundary ◽  
Antiphase Domain ◽  
Iron Aluminides ◽  
Stress Model ◽  
Theoretical Yield ◽  
Domain Boundaries ◽  
Ordered Intermetallic ◽  
Critical Resolved Shear Stress ◽  
B2 Structure ◽  
Type Crystal

The modified Peirel–Nabarro model of dislocations is not valid for the superdislocation bounded by the antiphase domain boundaries in long-range ordered intermetallic. In this work, a new Peirel–Nabarro Stress model is developed to take into account the critical resolved shear stress of antiphase domain boundary (APDB). Based on it, the Peirel–Nabarro Stress of DO3 structure and B2 structure in iron aluminides are calculated. Comparing the Peirel–Nabarro Stress of dislocations and the crystal theoretical yield strength, the results demonstrate B2-type crystal has good plasticity. It coincides with the experimental results well.

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