TEM observation of the channel regions in a two-phase intermetallic alloy based on Ni3Al–Ni3V pseudo-binary alloy system

2012 ◽  
Vol 21 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Taku Moronaga ◽  
Yasuyuki Kaneno ◽  
Hiroshi Tsuda ◽  
Takayuki Takasugi
Keyword(s):  
Binary Alloy ◽  
Alloy System ◽  
Intermetallic Alloy ◽  
Two Phase ◽  
Phase Intermetallic ◽  
Binary Alloy System

Microstructure Analysis of The Channel Regions in Dual Two-phase Intermetallic Alloy Based on The Ni3Al-Ni3V Pseudo-binary Alloy System

2011 ◽  
Vol 1295 ◽  
Author(s):  
T. Moronaga ◽  
Y. Kaneno ◽  
H. Tsuda ◽  
T. Takasugi
Keyword(s):  
High Temperature ◽  
Binary Alloy ◽  
Lattice Misfit ◽  
Alloy System ◽  
Dark Field ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Transmission Electron ◽  
Phase Intermetallic ◽  
Binary Alloy System

ABSTRACTDual two-phase intermetallic alloys based on the Ni3Al-Ni3V pseudo-binary alloy system have been reported to display high phase and microstructure stabilities and good mechanical properties at high temperature and are therefore considered to be used as a next generation type of high temperature structural materials. The microstructure of the dual two-phase intermetallic alloys is composed of primary Ni3Al and the channel (eutectoid) regions consisting of Ni3Al+Ni3V. In this study, the microstructure of the channel regions was investigated by a transmission electron microscope (TEM). The contrasts of the channel regions showed a complicated microstructure in bright-field images. However, the electron beam diffraction consisted of a single set of patterns and the spots did not accompany streaks, indicating that crystallographic coherency among the constituent phases or the domains is very high. It was also shown that the lattice misfit between the a-axis of Ni3Al and the c-axis of Ni3V is larger than that between the a-axis of Ni3Al and the a-axis of Ni3V. From the dark-field observation, it was found that the c-axis of Ni3V domains in the channel regions is oriented perpendicular to the interface between primary Ni3Al and Ni3V. Therefore, it is suggested that the crystallographic orientation of Ni3V in the channel regions is aligned in the manner of lowering an internal stress caused by the lattice misfit between primary Ni3Al precipitates and Ni3V domains.

The Effect of Alloying Elements on Microstructure and Strength Property of Dual Two-Phase Intermetallic Alloys Based on Ni3Al-Ni3V Pseudo-Binary Alloy System

2010 ◽  
Vol 654-656 ◽  
pp. 452-455
Author(s):  
K. Kawahara ◽  
T. Moronaga ◽  
Yasuyuki Kaneno ◽  
A. Kakitsuji ◽  
Takayuki Takasugi
Keyword(s):  
Alloy System ◽  
Interfacial Area ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Hardness Property ◽  
Phase Intermetallic ◽  
Binary Alloy System ◽  
Ti Addition ◽  
Solute Hardening ◽  
Additional Hardening

The microstructures and hardness property of dual two-phase intermetallic alloys that arecomposed of various kind of volume fractions of geometrically closed packed (GCP) Ni3Al(L12) and Ni3V(D022) phases were studied. The hardness of dual two-phase intermetallic alloys basically was explained by mixture rule in hardness between primary Ni3Al precipitates and eutectoid region.Nb and Ti addition raised the hardness of dual two-phase intermetallic alloys by solid solute hardening in the constituent phases.The additional hardening arising from interfacial area between primary Ni3Al precipitates and eutectoid region was also found. As temperature increases, theadditional hardening decreased for the base and Nb added alloys but decreased little for the Ti added alloys.

Effect of The Refractory Element Additions on Microstructure and Mechanical Property of Two-phase Intermetallic Alloys Based on The Ni3Al-Ni3V Pseudo-binary Alloy System

2011 ◽  
Vol 1295 ◽  
Author(s):  
T. Moronaga ◽  
S. Ishii ◽  
Y. Kaneno ◽  
H. Tsuda ◽  
T. Takasugi
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Alloy System ◽  
Solid Solution Hardening ◽  
Refractory Element ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Rich Phase ◽  
Phase Intermetallic ◽  
Binary Alloy System

ABSTRACTTwo-phase intermetallic alloys composed of geometrically close packed (GCP) Ni3Al (L12 phase) and Ni3V (D022 phase) have attractive mechanical properties at high temperature, and are therefore considered to be used as high temperature structural materials. In this study, the effect of Ta and Re addition on the microstructure and hardness of two-phase intermetallic alloys was investigated. The addition of Ta remarkably enhanced the hardness due to solid solution hardening of the constituent phases. On the other hand, the addition of Re retarded the formation of the two-phase microstructure, resulting in the lowest hardness in the solution treated condition. By aging at 1223 K, the Ni solid solution in the Re added alloy decomposed to Ni3Al and Ni3V, accompanied by precipitates of a Re-rich phase. Consequently, the hardness rapidly increased with increasing aging time. Simultaneous addition of Ta and Re induced very fine precipitates of a Re-rich phase after aging, and consequently resulted in a higher hardness than by the addition of Ta or Re alone.

Effect of Si Addition on Microstructure and Mechanical Properties of Dual Two-Phase Intermetallic Alloys Based on the Ni3Al-Ni3V Pseudo-Binary Alloy System

2015 ◽  
Vol 1760 ◽  
Author(s):  
Yuki Hamada ◽  
Yasuyuki Kaneno ◽  
Hiroshi Numakura ◽  
Takayuki Takasugi
Keyword(s):  
Mechanical Properties ◽  
Oxidation Resistance ◽  
Base Alloy ◽  
Tensile Elongation ◽  
Alloy System ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Microstructure And Mechanical Properties ◽  
Phase Intermetallic ◽  
Si Addition

ABSTRACTThe effect of Si addition on microstructure and mechanical properties of dual two-phase intermetallic alloys was investigated. Si was added to the base alloy composition Ni75Al9V13Nb3 + 50 wt. ppm B by three substitution ways in which Si was substituted either for Ni, for Al and for V, respectively. The alloys added with 1 at.% Si showed a dual two-phase microstructure composed of Ni3Al (L12) and Ni3V (D022) phases, while the alloys added with over 2 at.% Si exhibited the same dual two-phase microstructure but contained third phases. The third phases were G phase (Ni16Si7Nb6) and A2 phase (the bcc solid solution consisting of Nb and V). Yield and tensile strength of the 1 at.% Si-added alloys were high in the alloy in which Si was substituted for Al but low in the alloys in which Si was substituted for Ni or for V, in comparison with those of the base alloy. Tensile elongation was lower than that of the base alloy irrespective of substitution ways. The density of the Si added alloys was close to or slightly lower than that of the base alloy. Oxidation resistance of the Si added alloy was increased. Si addition to the dual two-phase intermetallic alloys is beneficial for reducing the density and enhancing the oxidation resistance without a harmful reduction of strength properties.

Coherency Strain of an Overgrown Island

1989 ◽  
Vol 148 ◽  
Author(s):  
J. K. Lee ◽  
S. A. Hackney
Keyword(s):  
Single Phase ◽  
Lattice Misfit ◽  
Alloy System ◽  
Misfit Strain ◽  
Chemical Thermodynamics ◽  
Misfit Dislocations ◽  
Two Phase ◽  
Single Phase State ◽  
Ε Phase ◽  
Binary Alloy System

ABSTRACTThe lattice misfit strain in an overgrown island is considered to be accommodated by twodistinctive domains; a pure coherency domain (ε domain) and a domain of misfit dislocations (δ domain). By introducing such two different constituents, the model predicts the transition condition from a “single phase” state (ε phase) to a “two-phase mixture” (ε+δ) as a function of misfit strain. Further, as in the chemical thermodynamics of a binary alloy system, energy vs. misfit strain diagrams allow us to understand possible existence of various metastable states which may be associated with an overgrowth.

Superplasticity and hot rolling of two-phase intermetallic alloy based on TiAl

1996 ◽  
Vol 34 (6) ◽  
pp. 985-991 ◽  
Author(s):  
R. Imayev ◽  
M. Shagiev ◽  
G. Salishchev ◽  
V. Imayev ◽  
V. Valitov
Keyword(s):  
Hot Rolling ◽  
Intermetallic Alloy ◽  
Two Phase ◽  
Phase Intermetallic

Microstructures and hardness properties of laser clad Ni base two-phase intermetallic alloy coating

2017 ◽  
Vol 32 (24) ◽  
pp. 4531-4540 ◽  
Author(s):  
Takeshi Okuno ◽  
Yasuyuki Kaneno ◽  
Takuto Yamaguchi ◽  
Satoshi Semboshi ◽  
Hideki Hagino ◽  
...  
Keyword(s):  
Alloy Coating ◽  
Intermetallic Alloy ◽  
Two Phase ◽  
Phase Intermetallic ◽  
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