Effect of compositional modification on ductility of B2 phase in Ti–Al–Nb intermetallic alloy

2002 ◽  
Vol 17 (10) ◽  
pp. 2611-2614 ◽  
Author(s):  
Feng Tang ◽  
Masuo Hagiwara
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Phase State ◽  
Intermetallic Alloy ◽  
Chemical Compositions ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Room Temperature Ductility ◽  
Single Phase State ◽  
B2 Phase

Room-temperature ductility of two Ti–Al–Nb intermetallic alloys with close chemical compositions was investigated by tensile testing. The two alloys' ductilities in the B2 single-phase state were significantly different, which indicated that the ductility of B2 phase state was sensitive to the chemical composition. The alloy with more ductile B2 phase exhibited higher ductility in O + B2 two-phase state.

scholarly journals Investigation and application of wellbore temperature and pressure field coupling with gas–liquid two-phase flowing

2021 ◽  
Author(s):  
Jie Zheng ◽  
Yihua Dou ◽  
Zhenzhen Li ◽  
Xin Yan ◽  
Yarong Zhang ◽  
...  
Keyword(s):  
Single Phase ◽  
Phase State ◽  
Pressure Field ◽  
Coupling Model ◽  
High Water ◽  
Two Phase ◽  
Gas Well ◽  
Single Phase State ◽  
Wellbore Temperature ◽  
Temperature And Pressure

AbstractWith the development of gas well exploitation, the calculation of wellbore with single-phase state affected by single factor cannot meet the actual needs of engineering. We need to consider the simulation calculation of complex wellbore environment under the coupling of multiphase and multiple factors, so as to better serve the petroleum industry. In view of the problem that the commonly used temperature and pressure model can only be used for single-phase state under complex well conditions, and the error is large. Combined with the wellbore heat transfer mechanism and the calculation method of pipe flow pressure drop gradient, this study analyzes the shortcomings of Ramey model and Hassan & Kabir model through transient analysis. Based on the equations of mass conservation, momentum conservation and energy conservation, and considering the interaction between fluid physical parameters and temperature and pressure, the wellbore pressure coupling model of water-bearing gas well is established, and the Newton Raphael iterative method is used for MATLAB programming. On this basis, the relationship between tubing diameter, gas production, gas–water ratio, and wellbore temperature field and pressure field in high water-bearing gas wells is discussed. The results show that the wellbore temperature pressure coupling model of high water-bearing gas well considering the coupling of gas–liquid two-phase flow wellbore temperature pressure field has higher accuracy than Ramey model and Hassan & Kabir model, and the minimum coefficients of variation of each model are 0.022, 0.037 and 0.042, respectively. Therefore, the model in this study is highly consistent with the field measured data. Therefore, the findings of this study are helpful to better calculate the wellbore temperature and pressure parameters under complex well conditions.

Compendium of alloy phases observed after low temperature aging of Ni-rich NiAl

1990 ◽  
Vol 48 (4) ◽  
pp. 944-945
Author(s):  
Ivan E. Locci ◽  
P. S. Khadkikar ◽  
R. D. Noebe ◽  
K. Vedula
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Tensile Ductility ◽  
Intermetallic Alloys ◽  
Directionally Solidified ◽  
Two Phase ◽  
Low Temperature Aging ◽  
Temperature Aging ◽  
Stable And Metastable Phases

An overwhelming amount of research has been performed on Ni3Al (γ’) and NiAl (β) intermetallic alloys over the last decade. Yet, very little is known about the two phase field between these ordered compounds, including the occurrence and stability of phases other than γ’ or β Identifying and understanding these other phases are important since one approach to improving the ductility and toughness of NiAl is to design an alloy with a dual phase microstructure (i.e. NiAl + Ni3Al). Preliminary alloying attempts have encountered varying degrees of success. They range from powder metallurgy alloys with significantly increased fracture strengths over single phase (β-alloys to directionally solidified γ’ + β crystals which exhibit up to 9% tensile ductility at room temperature. Unfortunately, aging of these alloys at low temperature (<973 K) results in the formation of several complex, stable and metastable phases which may negate any original improvements in mechanical behavior.

Deformation Microstructures of Two-Phase Intermetallic Alloy Composed of Ni3Al and Ni3V in Single Crystalline Form

2012 ◽  
Vol 706-709 ◽  
pp. 1077-1082 ◽  
Author(s):  
T. Moronaga ◽  
Yasuyuki Kaneno ◽  
Hiroshi Tsuda ◽  
Takayuki Takasugi
Keyword(s):  
Room Temperature ◽  
Dislocation Motion ◽  
Intermetallic Alloy ◽  
High Flow ◽  
Crystalline Form ◽  
Intermetallic Alloys ◽  
Flow Strength ◽  
Two Phase ◽  
Transmission Electron ◽  
Phase Intermetallic

Two-phase single-crystal intermetallic alloys composed of Ni3Al (L12) and Ni3V (D022) with some orientations were compressed at various temperatures, and their deformation microstructures were observed by transmission electron microscopy (TEM). The deformation at room temperature was governed by the glide motion of dislocations in the primary Ni3Al precipitates and the activation of the microtwins in the Ni3V variant structures in the channel regions. The interfaces between the primary Ni3Al precipitates and the Ni3V variant structures are suggested to work as the barriers to the dislocation motion. While, at temperature above the peak temperature (873 K), the deformation microstructures of the two-phase intermetallic alloy exhibited the ribbon-like deformation microstructures penetrating the constituent phases i.e. through the interfaces between primary Ni3Al precipitates and the Ni3V variant structures in the channel regions. It was also suggested that the superior strength in the two-phase intermetallic alloys is due to the high flow strength of the Ni3V phases and to the interfacial hardening receiving when the dislocations activated in the primary Ni3Al precipitates propagate to the channel regions.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

Methods of Stabilization of Gas Condensates

2018 ◽  
Author(s):  
Ibukun Makinde
Keyword(s):  
Single Phase ◽  
Phase State ◽  
Liquid Mixtures ◽  
Gas Condensate ◽  
Liquid Hydrocarbons ◽  
Light Hydrocarbons ◽  
Natural Gases ◽  
Gas Condensates ◽  
Single Phase State

Gas condensates are liquid mixtures of high-boiling hydrocarbons of various structures, separated from natural gases during their production at gas condensate fields. When transporting gas through pipelines, the following gas quality conditions should be met:i.During transportation, gases should not cause corrosion of pipelines, fittings, instruments, etc.ii.The quality of the gas must ensure its transportation in a single-phase state i.e., liquid hydrocarbons, gas condensates and hydrates should not form in the pipelines.In order for gas condensates to meet the above-mentioned quality conditions during storage or transportation, they must be stabilized. Gas condensate stabilization is the process of “boiling off” light hydrocarbons from the condensate that would otherwise increase the vapor pressure when conditions are fluctuating.

scholarly journals An experimental and theoretical investigation of diffusion in a two-phase alloy

1948 ◽  
Vol 192 (1031) ◽  
pp. 575-592 ◽  
Keyword(s):  
Free Energy ◽  
Single Phase ◽  
Phase State ◽  
Theoretical Treatment ◽  
Research Association ◽  
Essential Difference ◽  
Two Phase ◽  
Two Factors ◽  
Order Of Magnitude ◽  
The Difference

The present paper describes an investigation of diffusion in the solid state. Previous experimental work has been confined to the case in which the free energy of a mixture is a minimum for the single-phase state, and diffusion decreases local differences of concentration. This may be called ‘diffusion downhill’. However, it is possible for the free energy to be a minimum for the two-phase state; diffusion may then increase differences of concentration; and so may be called ‘diffusion uphill’. Becker (1937) has proposed a simple theoretical treatment of these two types of diffusion in a binary alloy. The present paper describes an experimental test of this theory, using the unusual properties of the alloy Cu 4 FeNi 3 . This alloy is single phase above 800° C and two-phase at lower temperatures, both the phases being face-centred cubic; the essential difference between the two phases is their content of copper. On dissociating from one phase into two the alloy develops a series of intermediate structures showing striking X-ray patterns which are very sensitive to changes of structure. It was found possible to utilize these results for a quantitative study of diffusion ‘uphill’ and ‘downhill’ in the alloy. The experimental results, which can be expressed very simply, are in fair agreement with conclusions drawn from Becker’s theory. It was found that Fick’s equation, dc / dt = D d2c / dx2 , can, within the limits of error, be applied in all cases, with the modification that c denotes the difference of the measured copper concentration from its equilibrium value. The theory postulates that D is the product of two factors, of which one is D 0f the coefficient of diffusion that would be measured if the alloy were an ideal solid solution. The theory is able to calculate D/D 0 , if only in first approximation, and the experiments confirm this calculation. It was found that in most cases the speed of diffusion—‘uphill’ or ‘downhill’—has the order of magnitude of D 0 . * Now with British Electrical Research Association.

Electronic irradiation of TlInSxSe2−x (x = 1): Morphology, structure and raman scattering

2021 ◽  
Author(s):  
M. Yu. Tashmetov ◽  
F. K. Khallokov ◽  
N. B. Ismatov ◽  
I. I. Yuldashova ◽  
S. Kh. Umarov
Keyword(s):  
Surface Morphology ◽  
Single Crystal ◽  
Single Phase ◽  
Phase State ◽  
Monoclinic Structure ◽  
Average Value ◽  
Single Phase State ◽  
Before And After ◽  
Electronic Irradiation ◽  
The Difference

It is shown that the replacement of a part of sulfur atoms with selenium atoms in a TlInS2 single crystal stimulates the formation of a single-phase state with a monoclinic structure (space group [Formula: see text]/[Formula: see text] in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation with 2 MeV electrons and a fluence of [Formula: see text] electron/cm2 of powder TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) leads to an increase in the crystallite size from 56.5 nm to 65 nm, which is most likely associated with a decrease in the interface. The difference between the surface morphology of the synthesized TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal and the surface morphology of the TlInS2 single crystal is established, which consists in a decrease in the height and width of the roughness in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation of a TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal with electrons with a fluence of [Formula: see text] electron/cm2 does not lead to a change in the height of the tubercle on its surface, and the average value of its width increases more than ten-fold. The identity of the peaks in the Raman spectra of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal before and after its irradiation with electrons with an energy of 2 MeV and upto a fluence of [Formula: see text] electron/cm2, along with the absence of a shift of the peaks, indicates the radiation resistance of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal.

scholarly journals Ferromagnetic Order in the Intermetallic Alloys laNi5-xMgx

2012 ◽  
Vol 29 (1) ◽  
pp. 50
Author(s):  
D.N Ba ◽  
L.T Tai ◽  
N.T Trung ◽  
N.T Huy
Keyword(s):  
Magnetic Properties ◽  
Curie Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Chemical Doping ◽  
Intermetallic Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferromagnetic Order ◽  
Diffraction Patterns

The influences of the substitution of Ni with Mg on crystallographic and magnetic properties of the intermetallic alloys LaNi5-xMgx (x ≤ 0.4) were investigated. The X-ray diffraction patterns showed that all samples were of single phase, and the lattice parameters, a and c, decreased slightly upon chemical doping. LaNi5 is well known as an exchange-enhanced Pauli paramagnet. Interestingly, in LaNi5-xMgx, the ferromagnetic order existed even with a small amount of dopants; the Curie temperature reached the value of room temperature for x = 0.2, and enhanced with increasing x.

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