Effects of microstructure on high temperature mechanical properties of Al3Ti–Mo3Al two-phase intermetallic alloys

2004 ◽  
Vol 12 (7-9) ◽  
pp. 771-777 ◽  
Author(s):  
Seiji Miura ◽  
Hiroyuki Shimamura ◽  
Juri Fujinaka ◽  
Tetsuo Mohri
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
High Temperature Mechanical Properties ◽  
Phase Intermetallic

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.

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.

The disordering process in an Ll2 ordered alloy

1984 ◽  
Vol 42 ◽  
pp. 486-487
Author(s):  
J. A. Horton ◽  
A. DasGupta ◽  
C. T. Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Intermetallic Alloys ◽  
Antiphase Boundaries ◽  
High Temperature Mechanical Properties ◽  
Heat Treated ◽  
Ordered Intermetallic

Ordered intermetallic alloys potentially have good high temperature mechanical properties which often are obtained by macroalloying. Since service temperatures may be near the critical ordering temperature, Tc, it is important to understand the disordering processes. The disordering mechanism in an alloy of 52.5 at. % Ni—22.5 Fe—14.5 V—10 Al—0.5 Ti [which can be expressed as (Ni70Fe30)3(V58Al40Ti2)], will be presented here. The aluminum was added to increase Tc from 750 to 975°C and stabilize the Ll2 structure.All specimens were first fully ordered by a heat treatment consisting of 30 min at 1000°C, 1 d at 700°C and 2 d at 600°C which results in a “swirl” pattern of antiphase boundaries (APB) similar to Fig. 1. Specimens were then heat-treated for 24 h at temperatures from 600 to 950°C in 50°C increments and water quenched.

Microstructure and Mechanical Properties of Dual Two-Phase Intermetallic Alloys Composed of GCP Ni3Al and Ni3V Phases containing Nb

2006 ◽  
Vol 980 ◽  
Author(s):  
Wataru Soga ◽  
Yasuyuki Kaneno ◽  
Takayuki Takasugi
Keyword(s):  
High Temperature ◽  
Creep Test ◽  
Alloy System ◽  
High Yield ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Electron Microscopies ◽  
Compression Creep ◽  
Phase Intermetallic ◽  
Multi Phase

AbstractDual multi-phase intermetallic alloys composed of Ni3X (X: Al and V) containing Nb were developed, on the basis of the Ni3Al-Ni3Nb-Ni3V pseudo-ternary alloy system. The dual multi-phase intermetallic alloys were characterized by scanning electron and transmission electron microscopies. High-temperature compression and tension tests, and compression creep test were conducted. It was found that the dual multi-phase intermetallic alloys show high yield and tensile strength with good temperature retention, accompanied with reasonable tensile ductility. The compression creep test conducted at high temperature showed lower creep rate in the dual multi-phase intermetallic alloys than in conventional Ni-base superalloys. The obtained results are superior to the dual multi-phase intermetallic alloys containing Ti.

Microstructure and Mechanical Properties of Dual Multi-Phase Intermetallic Alloys Composed of Geometrically Close Packed Ni3X Structures

2007 ◽  
Vol 561-565 ◽  
pp. 375-378
Author(s):  
Takayuki Takasugi ◽  
Yasuyuki Kaneno
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Ductility ◽  
High Yield ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Low Temperature Annealing ◽  
Wide Range ◽  
Phase Intermetallic ◽  
Multi Phase

Dual two-phase intermetallic alloys composed of geometrically close packed (GCP) structures of Ni3Al(L12) and Ni3V(D022) containing Nb were investigated in terms of the microstructural evolution during low temperature annealing (aging) and the related mechanical properties. The eutectoid region, i.e. the prior Al phase (Ni solid solution) is composed of the lamellar-like structure consisting of Ni3Al(L12) and Ni3V(D022) phases. The lamellar-like structure tended to align along <001> direction and on {001} plane in the prior A1 phase (or the L12 phase). In a wide range of temperature, the dual two-phase intermetallic alloys showed high yield and tensile strength, and also reasonable tensile ductility, accompanied with ductile fracture mode.

scholarly journals Deformation Twinning in Ordered Intermetallic Compounds

1988 ◽  
Vol 133 ◽  
Author(s):  
M. H. Yoo ◽  
C. L. Fu ◽  
J. K. Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Intermetallic Compounds ◽  
Deformation Twinning ◽  
Intermetallic Alloys ◽  
High Temperature Mechanical Properties ◽  
Ordered Intermetallic ◽  
Specific Calculations ◽  
Superlattice Structures

ABSTRACTMechanistic understanding of deformation twinning in ordered superlattice structures is reviewed, and the inter-relationships between twinning and generalized plastic flow or fracture toughness are discussed. While general discussions refer to all the fcc-based and bcc-based cubic and noncubic ordered intermetallic alloys, specific calculations of the energetic and kinetic aspects of deformation twinning are made for TiAl. The importance of the twin-slip conjugate relationship on high temperature mechanical properties is emphasized. Discussion is given of possible effects of macro- and micro-alloying on twinning propensity.

Strength and Toughness of Be12Nb, Be17 Nb2 and Two-Phase Be12Nb-Be17Nb2

1992 ◽  
Vol 273 ◽  
Author(s):  
Stephen M. Bruemmer ◽  
Bruce W. Arey ◽  
Charles H. Henager
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Intermetallic Compounds ◽  
Compression Strength ◽  
Bend Strength ◽  
Two Phase ◽  
High Temperature Mechanical Properties ◽  
Strength And Toughness

ABSTRACTBend strength, compression strength, and fracture toughness of niobium beryllide intermetallic compounds have been assessed at temperatures from ambient to 1200°C. Hot-isostatically-pressed (HIP) Be12Nb showed significantly improved lowand high-temperature mechanical properties over vacuum-hot-pressed (VHP) material. Strengths at 20°C were 250 MPa in bending and 2750 MPa in compression with a fracture toughness of ∼4 Mpa√m, much higher than previously measured for this compound. High-temperature (≥ 1000°C) mechanical properties were also improved with bend strengths of 250 MPa at 1200°C as compared to only 70 to 100 MPa for the VHP material. However, severe pest embrittlement was detected in the HIP material at temperatures between 650 and 1000°C.

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