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Article

Age-Induced Precipitation and Hardening Behavior of Ni3Al Intermetallic Alloys Containing Vanadium

by
Satoshi Semboshi
1,*,
Ryosuke Sasaki
2,
Yasuyuki Kaneno
2 and
Takayuki Takasugi
2
1
Institute for Materials Research, Tohoku University; Katahira 2-1-1, Aoba-ku, Sendai, Miyagi 980-8577, Japan
2
Department of Materials Science, Osaka Prefecture University; Gakuen-cho 1-1, Naka-ku, Sakai, Osaka 599-8531, Japan
*
Author to whom correspondence should be addressed.
Metals 2019, 9(2), 160; https://doi.org/10.3390/met9020160
Submission received: 25 December 2018 / Revised: 26 January 2019 / Accepted: 30 January 2019 / Published: 1 February 2019
(This article belongs to the Special Issue Intermetallic Alloys)
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Abstract

:
L12-type Ni3Al alloys containing vanadium are potential candidates for solid-solution and age-hardenable alloy systems, according to the Ni3Al-Ni3V pseudo-binary phase diagram. Therefore, herein, variations in the microstructure and mechanical properties of Ni-13 at.% Al-12 at.% V-50 ppm B alloy during isothermal aging were investigated. Alloy specimens were solution-treated at 1323 K for 48 h, quenched in water, and aged at 1073 K to 1173 K. The quenched specimens exhibited a single phase of Ni3Al (L12 structure derived from Al (fcc) structure), while in the aged specimens, numerous fine disk-shaped precipitates identified as Ni3V (D022 structure from orthorhombic structure) were formed on {001} planes of the Ni3Al matrix. The size of the disk-shaped Ni3V precipitates increased gradually with increasing aging period. The hardness and strength of the specimens increased initially during aging at 1073 K to 1173 K, reached a maximum, followed by a subsequent decrease. The age-hardening behavior observed for the specimens can be explained in terms of precipitation of the fine disk-shaped Ni3V precipitates in the Ni3Al matrix. Furthermore, the peak-aged specimens exhibited an increase in yield strength with increasing testing temperature, similar to other L12-type intermetallic alloys.

1. Introduction

Ni3Al-based alloys offer several advantages such as high melting point, excellent mechanical properties at high temperatures, high thermal conductivity, good oxidization resistance, and low density, which are prerequisites for the vehicle components used in high-temperature applications such as engines and turbine blades. With the development of novel high-temperature materials, Ni3Al intermetallic compounds with the L12 structure derived from the A1 (fcc) structure play an important role as the primary phase for single-phase Ni3Al-based alloys, [1,2,3,4,5,6,7,8,9,10,11] Ni3Al/Ni3V for dual two-phase alloys [12,13,14,15], and the dispersive strengthening phase for Ni-based superalloys [16,17,18,19,20]. However, Ni3Al-based alloys suffer from poor ductility at ambient temperature and therefore, fundamental and practical efforts to improve not only the strength at low and high temperatures but also the intrinsic deformability of the Ni3Al phase have been of significant interest.
In order to provide an excellent combination of mechanical properties of Ni3Al-based alloys, the Ni3Al phase should be modified by alloying and microstructural optimization. For example, a drastic increase in the ductility of Ni3Al obtained by boron doping has been reported [21,22,23,24]. Further, there have been numerous investigations on Ni3Al-based alloys strengthened by solid-solution hardening via the elemental addition of Ti, Cr, Nb, and Ta [25,26,27]. There have also been studies on alloys strengthened by the dispersion of soft precipitates of a Ni solid solution [28,29], and hard particles such as ceramics and oxides [30,31,32]. However, to meet the current requirement of high-performance components, further enhancement of the mechanical, and physical properties of Ni3Al-based alloys is crucial.
Alloys based on the Ni3Al-Ni3V pseudo-binary alloy system should be potential solid-solution and aged-hardenable alloys, because vanadium dissolves well in the L12 Ni3Al phase and largely supersaturates at a eutectoid temperature, as shown in Figure 1 [33]. It is also expected that age-induced hardening due to the precipitation of hard Ni3V with the D022 structure can improve the strength without significant degradation of other properties, such as thermal conductivity and environmental resistance [34,35]. The mechanical properties of Ni3Al alloys were improved by adding 1–2 at.% of vanadium [26,27]; however, there is no study on the mechanical properties of Ni3Al alloys containing a large amount of vanadium. Further, there have only been few reported attempts to demonstrate the age-hardening behavior in the Ni3Al-Ni3V system. Hence, in this study, we strengthened Ni3Al alloys through the fine dispersion of age-induced precipitates, as well as through the dissolution of solutes in the matrix, by which the dislocation motion was hindered even at high temperatures. We then examined variations in the microstructure and mechanical properties during isothermal aging for a Ni3Al alloy containing a large amount of vanadium.

2. Materials and Methods

Based on the phase diagram of the Ni3Al–Ni3V pseudo-binary alloy system (Figure 1; [33]), single-phase L12 Ni3Al alloys with the nominal composition of Ni-25 at.% Al-50 wt. ppm B and Ni-13 at.% Al-12 at.% V-50 wt. ppm B were prepared. Here, a small amount (50 wt. ppm) of B was doped on both alloys in order to improve the ductility of the parent Ni3Al phase through the suppression of intergranular fracture [21,22,23,24]. Hereafter, these alloys are denoted as Ni3Al-0V and Ni3Al-12V alloys, respectively. Alloy button ingots with a diameter of 30 mm or 50 mm were fabricated by arc-melting in argon atmosphere using a non-consumable tungsten electrode on a copper hearth. Pure nickel grains (99.99 wt.% in purity), aluminum tips (99.9 wt.%), vanadium grains (99.9 wt.%), and boron powder (99.9 wt.%) were used as raw materials. The button ingots were melted repeatedly at least four times to ensure complete chemical homogeneity, and were then cut into sample pieces using an electro-discharge machine. After the contaminated layer was removed from the specimen surface by mechanical grinding, the pieces were encapsulated in a quartz tube, in which the pressure was maintained to be less than 2.0 × 10−3 Pa. Subsequently, the encapsulated specimens were heat-treated at 1323 K for 48 h and quenched in water, to obtain single-phase L12 Ni3Al with and without vanadium. Some Ni3Al-12V alloy specimens were encapsulated again under a vacuum of less than 2.0 × 10−3 Pa in a quartz tube, and then isothermally aged at 1073 K, 1123 K, and 1173 K for various durations from 1 h to 240 h, followed by quenching in water.
The microstructures of the specimens were investigated by conventional field-emission scanning electron microscopy (FESEM) using a JSM-7001F (JOEL Inc., Tokyo, Japan),, and transmission electron microscopy (TEM) using a JEM-2000FX (JOEL Inc., Tokyo, Japan) operated at an accelerating voltage of 200 kV. Specimens for TEM observations were first mechanically abraded to less than 30 μm in thickness using SiC paper, and then polished by low-angle ion milling using a PIPS (Gatan Inc., Tokyo, Japan) with an argon ion beam accelerated at 3.5 kV. Hardness measurements were carried out using a Vickers microhardness tester HM-101 (Mitsutoyo Inc., Tokyo, Japan) under an applied load of 4.9 N for a dwell time of 10 s. The average hardness was obtained from more than 10 indentations. Tensile tests were performed using a universal tensile testing machine TENSIRON UTA-10 KN (A&D Co. Ltd., Tokyo, Japan) at temperatures ranging between room temperature (298 K) and 1073 K with an initial strain rate of 1.67 × 10−4 s−1 under a vacuum of less than 2.0 × 10−3 Pa. For the tensile tests, dog-bone-shaped specimens with a cross-section of 2 mm × 1.5 mm and gauge length of 10 mm were used.

3. Results and Discussion

3.1. Microstructure

Figure 2 shows typical FESEM and bright-field (BF) images and a corresponding selected-area electron diffraction (SAED) pattern of the Ni3Al-12V alloy specimen quenched from 1323 K. The specimens obtained through casting, annealing, and then quenching comprise relatively coarse grains with sizes ranging from 100 μm to 1 mm, as observed in Figure 2a. There are no contrasts from second phases in the matrix phase (Figure 2a,b), although few strain contrasts from dislocations are observed in Figure 2b. The SAED pattern (Figure 2c), which was taken from the matrix phase, indicates that all the fundamental and superlattice reflections can be indexed to the L12 structure of the Ni3Al phase (lattice parameter, a = 0.356 nm), as illustrated schematically in Figure 2d. Thus, we confirmed that the Ni3Al-12V alloy specimen quenched from 1323 K comprised a single phase of L12 Ni3Al containing vanadium element. This indicates that the solubility limit of vanadium for the L12 Ni3Al phase at 1323 K (Figure 1) should be more than 12 at.%.
Figure 3a shows a BF image of the Ni3Al-12V alloy specimen isothermally aged at 1123 K for 4 h. The incident beam direction is close to the [001]m zone axis (the subscript “m” denotes the L12 Ni3Al matrix phase). We can see dark contrasts, with a length of approximately 1 μm, extended preferentially along the [100]m and [010]m directions, as indicated by the arrows in Figure 3a. Figure 3b shows a SAED pattern taken from the extended dark contrasts (dotted circle in Figure 3a). The SAED pattern was identified by a superposition of reflections from the L12 Ni3Al matrix shown in Figure 2c, and the Ni3V with a D022 structure from the orthorhombic structure with lattice parameters a = 0.355 nm and c = 0.719 nm, as marked by the diamond shapes in Figure 3c. Thus, the precipitates introduced by aging at 1123 K were identified as D022 Ni3V, which was predicted from the phase diagram of Figure 1. The orientation relationship between the Ni3Al matrix and Ni3V precipitates was [001]m//[001]p, (100)m//(100)p (the subscript “p” denotes the precipitate phase of Ni3V with a D022 structure).
Figure 4 shows the BF images of the Ni3Al-12V alloy specimen isothermally aged at 1123 K for 16 h and 48 h. The incident beam direction is close to the [001]m zone axis. We can see dark contrasts from Ni3V precipitates, which extend preferentially along the [100]m and [010]m directions, similar to those in Figure 3a. There are two shapes of contrasts of the Ni3V precipitates; i.e., extended elliptical (indicated by arrows in Figure 4b) and almost circular (dotted circle) ones. This suggests that the D022 Ni3V precipitates in the L12 Ni3Al matrix should be dispersed preferentially along (001)m with a disk-like shape (Figure 5). The size and aspect ratio of the Ni3V precipitates appear to increase with aging time. The diameter is approximately 1.5 μm for 16 h of aging and 2 μm for 48 h of aging; both exhibit a similar thickness of 0.5 μm. Here, the misfit strains along the a- and c-axes on the matrix plane with the precipitates are estimated to be approximately 0.3% and 0.8%, respectively, because the lattice parameters of L12 Ni3Al and D022 Ni3V in the two-phase region have been reported as a = 0.356 nm, and a = 0.355 nm, and c = 0.719 nm respectively [36]. Therefore, the disk-like two-dimensional growth of D022 Ni3V precipitates, which have coherent broad faces on the (001)m planes containing the a- and b-axes of the matrix, should be caused by the minimization of the interface energy between the L12 Ni3Al matrix and the D022 Ni3V precipitates [37].

3.2. Mechanical Properties

Figure 6 shows the variation in the Vickers hardness of the Ni3Al-12V alloy specimens during isothermal aging at 1073 K, 1123 K, and 1173 K. The hardness for all three aging temperatures increases initially, reaches a maximum value, and then decreases for the specimens that underwent prolonged aging. The value of the maximum hardness decreases with increasing aging temperature, while the period to reach the maximum hardness is shortened.
The age-hardening behavior might be common with some conventional age-hardenable Al, Cu, and Fe alloy systems [38,39,40,41], and can be, in this case, explained by the precipitation of D022 Ni3V. In the initial stage of aging, the hardness steadily increased with the nucleation and growth of D022 Ni3V precipitates in the L12 Ni3Al matrix phase. The maximum hardness is associated with the maximum number of D022 Ni3V precipitates. This implies that the continuous nucleation of D022 Ni3V precipitates is saturated, due to the depletion of super-saturated solid-solute vanadium atoms in the matrix. The hardness decreases with further aging due to an increase in the distance between the D022 Ni3V precipitates, which might be because the precipitates undergo Ostwald ripening, like other age-hardenable alloys [38,39,41].
Figure 7 shows the typical nominal stress-strain curves at 298 K for the Ni3Al-12V alloy specimens quenched and peak-aged at 1123 K for 16 h, together with the quenched Ni3Al-0V alloy specimen for comparison. The quenched Ni3Al-0V alloy yields with mild plastic elongation, which is consistent with previous reports [2,7,10]. On the other hand, both, the quenched and aged Ni3Al-12V alloy specimens show a greater yield strength than the quenched Ni3Al-0V alloy specimen, followed by extensive work hardening accompanied by a larger fracture strain. The enhancement in yield strength for both specimens should be attributed primarily to solid-solution hardening by the vanadium atom dissolved in the L12 Ni3Al phase. Mishima et al. reported an increased rate of change in solid-solution hardening per atomic percent, (dσ/dc), for vanadium [27]. However, the detailed influence of a large amount of vanadium dissolving in the Ni3Al phase on the mechanical properties is still unclear. We are systematically investigating this and will report it in the future. The yield strength of the peak-aged Ni3Al-12V alloy specimen seemed to be slightly greater by 15 MPa than that of the quenched Ni3Al-12V alloy specimen. This must be due to the age-induced precipitates of D022 Ni3V in the L12 Ni3Al matrix phase. Nevertheless, yield strengthening by the age-induced precipitates should not be as significant as strengthening by the solid-solution effect of vanadium atoms.
Figure 8 shows the typical nominal stress-strain curves at elevated temperatures from 298 K to 1073 K for the Ni3Al-12V alloy specimens peak-aged at 1123 K for 16 h. The 0.2% yield strength is shown by arrows in Figure 8. Figure 9 summarizes the yield strength (0.2% proof stress), ultimate tensile strength, and fractural strain for the Ni3Al-12V alloy specimens quenched and peak-aged at 1123 K for 16 h as a function of the testing temperature. In comparison to the stoichiometric Ni-25 at.% Al binary alloy [10], the yield strengths of the quenched and peak-aged Ni3Al-12V alloy specimens at 298 K are higher, as described above. Notably, the yield strength of both specimens steadily increases with the testing temperature to 1073 K, indicating an anomalous temperature dependency of yield strength, similar to other L12 intermetallic compounds [1,2,42], while that of the stoichiometric Ni3Al binary alloy specimen shows a peak at around 800 K. The peak temperature at which the maximum flow strength is observed has been suggested to be associated with the transition of the slip system with temperature [3,43]. Accordingly, the result observed in Figure 9a indicates that the transition temperature of the slip system from <110>{111} to <110>{100} is raised due to the effect of the vanadium atom dissolving in the Ni3Al matrix phase.
The tensile strength and fracture stain for the quenched and peak-aged Ni3Al-12V alloy specimens were maximum around 673 K, and then decreased monotonically with increasing testing temperature. However, the fracture strain at the highest testing temperature of 1073 K was still above 8% for the peak-aged Ni3Al-12V alloy specimens, which is a significant improvement compared with the quenched Ni3Al-12V alloy. Figure 10 shows the FESEM fractographs of the peak-aged Ni3Al-12V alloy specimen tensile-tested at 298 K and 973 K, together with that of the quenched Ni3Al-0V tensile-tested at 298 K for comparison. For the former, most areas of the fracture surfaces show a ductile-like dimple pattern (Figure 10a,b). On the other hand, the latter shows a brittle grain boundary facet pattern (Figure 10c), as has been observed in previous studies [2,21,22]. The enhancement in the tensile strength as well as the fracture strain might be attributed to the enhanced grain boundary strength by the V solutes largely dissolving in the Ni3Al phase via suppressing intergranular fracture. A similar phenomenon has been observed in Ni3Al alloys containing a large amount of Mn [44,45] and Fe [46], and Ni3Si containing a large amount of Ti [47]. Moreover, the decrease in both, the tensile strength and fracture strain with increasing testing temperature for the peak-aged Ni3Al-12V alloy specimen, may be associated with the intrinsic temperature dependence of the Ni3Al phase matrix, e.g., the transition of the activated slip system [3,43].
When comparing the tensile data for the quenched and peak-aged Ni3Al-12V alloy specimens, the yield strength, ultimate tensile strength, and fracture strain of the aged specimen tended to be superior to those of the quenched specimen, rendering them favorable for application as high-temperature materials. The enhancement in the yield strength and ultimate tensile strength can be explained by age-induced hardening by the D022 Ni3V precipitates. However, the reason why both the ultimate-tensile strength and fracture strain of the Ni3Al-12V alloy specimens were improved by aging remains unclear at this stage and is scope for future work.

4. Conclusions

In this study, we investigated the variations in the microstructure and mechanical properties during aging for L12 Ni3Al alloy containing a large amount of vanadium (nominal composition of Ni-13 at.% Al-12 at.% V-50 wt. ppm B), which was solution-treated at 1323 K for 48 h in vacuum and then quenched in water. The specimens quenched after solution treatment exhibited a single phase of L12 Ni3Al. For the specimens aged at 1123 K after 4 h, a number of fine disk-shaped precipitates were found on {001} planes of the L12 Ni3Al matrix. The disk-shaped precipitates were identified as D022 Ni3V. The size and aspect ratio of the disk-shaped Ni3V precipitates increased gradually with increasing aging time. The Vickers hardness of the quenched specimen was approximately 280 Hv. During aging at 1073 K to 1173 K, the hardness of the specimens increased and reached a maximum, then decreased. The age-hardening behavior observed for the Ni-13 at.% Al-12 at.% V alloy can be explained in terms of precipitation of the fine disk-shaped Ni3V phase in the Ni3Al matrix. The mechanical properties, such as yield strength, ultimate tensile strength, and fracture strain of the peak-aged Ni-13 at.% Al-12 at.% V alloy specimens at room temperature improved in comparison to the stoichiometric Ni3Al and quenched Ni-13 at.% Al-12 at.% V alloy. Moreover, the peak-aged alloy showed an anomalous temperature dependency of yield strength up to a maximum testing temperature of 1073 K. These features for the age-hardened Ni-13 at.% Al-12 at.% V alloy are desirable for applications as high-temperature structural materials.

Author Contributions

Conceptualization, S.S.; methodology, S.S. and R.S.; validation, Y.K. and T.T.; formal analysis, R.S.; investigation, R.S.; resources, Y.K.; data curation, S.S. and R.S.; writing—original draft preparation, S.S.; writing—review and editing, T.T.; supervision, T.T.

Funding

This research was funded by the Japan Society for the Promotion of Science (JSPS) as a Grant-in-Aid for Scientific Research (B) (No. 18H01743).

Acknowledgments

The authors thank N. Masahashi of the Institute for Materials Research (IMR) of Tohoku University and A. Iwase of Osaka Prefecture University for constructive discussion and comments. The authors also thank E. Aoyagi, S. Itoh, and I. Nagano of IMR of Tohoku University for their assistance with the experimental work. Technical support provided by the Cooperative Research and Development Center for Advanced Materials (CRDAM) of IMR is also greatly appreciated.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Noguchi, O.; Oya, Y.; Suzuki, T. The effect of non-stoichiometry on the positive temperature-dependence of strength of Ni3Al and Ni3Ga. Metall. Trans. A 1981, 12A, 1647–1654. [Google Scholar] [CrossRef]
  2. Pope, D.P.; Ezz, S.S. Mechanical properties of Ni3Al and nickel-base alloys with high volume fraction of γ′. Int. Metal. Rev. 1984, 29, 136–167. [Google Scholar]
  3. Suzuki, T.; Mishima, Y.; Miura, S. Evaluation of the data for the plastic behavior of Ni3(Al,X) single-crystals. Mater. Sci. Eng. A 1991, 146, 245–260. [Google Scholar] [CrossRef]
  4. Webb, G.; Debussac, A.; Antolovich, S.D. An analytical description for the deformation response of Ni3Al alloys in the anomalous regime. Metall. Trans. A 1993, 24A, 397–401. [Google Scholar] [CrossRef]
  5. Hirsch, P.B. A new theory of the anomalous yield stress in L12 alloys. Philos. Mag. A 1992, 65, 569–612. [Google Scholar] [CrossRef]
  6. Hemker, K.J.; Mills, M.J. Measurements of antiphase boundary and complex stacking-fault energies in binary and B-doped Ni3Al using TEM. Philos. Mag. A 1993, 68, 305–324. [Google Scholar] [CrossRef]
  7. Lapin, J. Effect of ageing on the microstructure and mechanical behavior of a directionally solidified Ni3Al-based alloy. Intermetallics 1997, 5, 615–624. [Google Scholar] [CrossRef]
  8. Demura, M.; Hirano, T. Stress response by the strain-rate change in a binary stoichiometric Ni3Al single crystal. Philos. Mag. Lett. 1997, 75, 143–148. [Google Scholar] [CrossRef]
  9. Demura, M.; Kishida, K.; Suga, Y.; Hirano, T. Room-temperature mechanical properties of cold-rolled thin foils of binary, stoichiometric Ni3Al. Metall. Mater. Trans. A 2002, 33A, 2607–2613. [Google Scholar] [CrossRef]
  10. Kruml, T.; Conforto, E.; Lo Piccolo, B.; Caillard, D.; Martin, J.L. From dislocation cores to strength and work-hardening: a study of binary Ni3Al. Acta Metall. 2002, 50, 5091–5101. [Google Scholar] [CrossRef]
  11. Wang, G.T.; Ding, H.S.; Chen, R.R.; Guo, J.J.; Fu, H.Z. Effect of current intensity on microstructure of Ni3Al intermetallics prepared by directional solidification electromagnetic cold crucible technique. Acta Metall. Sin. 2017, 53, 1461–1468. [Google Scholar]
  12. Nunomura, Y.; Kaneno, Y.; Tsuda, H.; Takasugi, T. Phase relation and microstructure in multi-phase intermetallic alloys based on Ni3Al-Ni3Ti-Ni3V pseudo-ternary alloy system. Intermetallics 2004, 12, 389–399. [Google Scholar] [CrossRef]
  13. Shibuya, S.; Kaneno, Y.; Yoshida, M.; Takasugi, T. Dual multi-phase intermetallic alloys composed of geometrically close packed Ni3X (X: Al, Ti and V) type structures-II. Mechanical properties. Acta Mater. 2006, 54, 861–870. [Google Scholar] [CrossRef]
  14. Kawahara, K.; Kaneno, Y.; Kakitsuji, A.; Takasugi, T. Microstructural factors affecting hardness property of dual two-phase intermetallic alloys based on Ni3Al-Ni3V pseudo-binary alloy system. Intermetallics 2009, 17, 938–944. [Google Scholar] [CrossRef]
  15. Edatsugi, D.; Kaneno, Y.; Semboshi, S.; Takasugi, T. Fine precipitation in channel region of two-phase Ni3Al and Ni3V intermetallic alloys containing Mo and W. Metall. Mater. Trans. A 2016, 47A, 998–1008. [Google Scholar] [CrossRef]
  16. Reed, R.C. The Superalloys: Fundamentals and Applications; Cambridge University Press: Cambridge, UK, 2008. [Google Scholar]
  17. Gopinath, K.; Gogia, A.K.; Kamat, S.V.; Balamuralikrishnan, R.; Ramamurty, U. Tensile properties of Ni-based superalloy 720Li: Temperature and strain rate effects. Metall. Mater. Trans. A 2008, 39A, 2340–2350. [Google Scholar] [CrossRef]
  18. Burns, D.E.; Zhang, Y.; Teutsh, M.; Bade, K.; Aktaa, J.; Hemker, K.J. Development of Ni-based superalloys for microelectromechanical systems. Scripta Mater. 2012, 67, 459–462. [Google Scholar] [CrossRef]
  19. Smith, T.M.; Bonacuse, P.; Sosa, J.; Kulis, M.; Evans, L. A quantifiable and automated volume fraction characterization technique for secondary and tertiary gamma’ precipitates in Ni-based superalloys. Mater. Charact. 2018, 140, 86–94. [Google Scholar] [CrossRef]
  20. Knowles, A.J.; Reynolds, L.; Vorontsov, V.A.; Dye, D. A nickel based superalloy reinforced by both Ni3Al and Ni3V ordered-fcc precipitates. Scripta Mater. 2019, 162, 472–476. [Google Scholar] [CrossRef]
  21. Aoki, K. Ductilization of L12 intermetallic compound Ni3Al by microalloying with boron. Mater. Trans. JIM 1990, 31, 443–448. [Google Scholar] [CrossRef]
  22. Liu, C.T.; White, C.L.; Horton, J.A. Effect of boron on grain-boundaries in Ni3Al. Acta Metall. 1985, 33, 213–229. [Google Scholar] [CrossRef]
  23. Taub, A.I.; Briant, C.L. Composition dependence of ductility in boron-doped, nickel-base L12 alloys. Acta Metall. 1987, 35, 1597–1603. [Google Scholar] [CrossRef]
  24. Varin, R.A.; Winnicka, M.B. Plasticity of structural intermetallic compounds. Mater. Sci. Eng. A 1991, 137, 93–103. [Google Scholar] [CrossRef]
  25. Ochiai, S.; Oya, Y.; Suzuki, T. Alloying behavior of Ni3Al, Ni3Ga, Ni3Si and Ni3Ge. Acta Metall. 1984, 32, 289–298. [Google Scholar] [CrossRef]
  26. Mishima, Y.; Ochiai, S.; Suzuki, T. Lattice-parameters of Ni(γ), Ni3Al(γ’) and Ni3Ga(γ’) solid-solutions with additions of transition and B-subgroup elements. Acta Metall. 1985, 33, 1161–1169. [Google Scholar] [CrossRef]
  27. Mishima, Y.; Ochiai, S.; Hamao, N.; Yodogawa, M.; Suzuki, T. Mechanical-properties of Ni3Al with ternary addition of transition-metal elements. Trans. JPN. Inst. Met. 1986, 27, 648–655. [Google Scholar] [CrossRef]
  28. Tain, W.H.; Sano, T.; Nemoto, M. Hardening of ordered γ′-Ni3(Al,Ti) by precipitation of ordered γ. Scripta Met. 1986, 20, 933–936. [Google Scholar]
  29. Ma, Y.; Ardell, J.A. Coarsening of γ (Ni–Al solid solution) precipitates in a γ′ (Ni3Al) matrix. Acta Mater. 2007, 55, 4419–4427. [Google Scholar] [CrossRef]
  30. Arzt, E.; Grahle, P. Dispersion strengthening of disordered and ordered metallic materials: From dislocation mechanisms to new alloys. Z. Metallkd. 1996, 87, 874–884. [Google Scholar]
  31. Arzt, E.; Behr, R.; Gohring, E.; Grahle, P.; Mason, R.P. Dispersion strengthening of intermetallics. Mater. Sci. Eng. A 1997, 234–236, 22–29. [Google Scholar] [CrossRef]
  32. Meng, J.; Jia, C.C.; He, Q. Fabrication of oxide-reinforced Ni3Al composites by mechanical alloying and spark plasma sintering. Mater. Sci. Eng. A 2006, 434, 246–249. [Google Scholar] [CrossRef]
  33. Kobayashi, S.; Sato, K.; Hayashi, E.; Osaka, T.; Konno, T.J.; Kaneno, Y.; Takasugi, T. Alloying effects on the phase equilibria among Ni(A1), Ni3Al(L1(2)) and Ni3V(D0(22)) phases. Intermetallics 2012, 23, 68–75. [Google Scholar] [CrossRef]
  34. Soffa, W.A.; Laughlin, D.E. High-strength age hardening copper-titanium alloys: redivivus. Prog. Mater. Sci. 2004, 49, 347–366. [Google Scholar] [CrossRef]
  35. Semboshi, S.; Tsuda, H.; Kanano, Y.; Iwase, A.; Takasugi, T. Thermal conductivity of Ni3V–Ni3Al pseudo-binary alloys. Intermetallics 2015, 59, 1–7. [Google Scholar] [CrossRef]
  36. Ioroi, K.; Kaneno, Y.; Semboshi, S.; Takasugi, T. Effect of transition metal addition on microstructure and hardening behavior of two-phase Ni3Al-Ni3V intermetallic alloys. Materialia. in press. [CrossRef]
  37. Porter, D.A.; Easterling, K.E. Phase Transformations in Metals and Alloys, 2nd ed.; CRC Press: Boca Raton, FL, USA, 2004; pp. 110–184. [Google Scholar]
  38. Lumley, R.N.; Polmear, I.J.; Morton, A.J. Interrupted aging and secondary precipitation in aluminium alloys. Mater. Sci. Technol. 2003, 19, 1483–1490. [Google Scholar] [CrossRef]
  39. Khan, I.N.; Starink, M.J.; Yan, J.L. A model for precipitation kinetics and strengthening in Al-Cu-Mg alloys. Mater. Sci. Eng. A 2008, 472, 66–74. [Google Scholar] [CrossRef]
  40. Semboshi, S.; Amano, S.; Fu, J.; Iwase, A.; Takasugi, T. Kinetics and equilibrium of age-induced precipitation in Cu−Ti binary alloys. Metall. Mater. Trans. A 2017, 48, 1501–1511. [Google Scholar] [CrossRef]
  41. Ma, J.; Hornbuckle, B.C.; Karaman, I.; Thompson, G.B.; Luo, Z.P.; Chumlyakov, Y.I. The effect of nanoprecipitates on the superelastic properties of FeNiCoAlTa shape memory alloy single crystals. Acta Mater. 1972, 61, 3445–3455. [Google Scholar]
  42. Kaneno, Y.; Myoki, T.; Takasugi, T. Tensile properties of L12 intermetallic foils fabricated by cold rolling. Int. J. Mater. Res. 2008, 99, 1229–1236. [Google Scholar] [CrossRef]
  43. Suzuki, T.; Mishima, Y.; Miura, S. Plastic Behavior in Ni3(Al,X) single-crystal-temperature, strain-rate, orientation and composition. ISIJ Int. 1989, 29, l–23. [Google Scholar] [CrossRef]
  44. Masahashi, N.; Takasugi, T.; Izumi, O. High-temperature strength and ductility of L12-type Ni3Al-Ni3Mn intermetallic compound. J. Mater. Sci. 1987, 22, 2599–2608. [Google Scholar] [CrossRef]
  45. Masahashi, N.; Takasugi, T.; Izumi, O. High-temperature strength and ductility of recrystallized Ni3Al-Ni3Mn alloys. Metall. Trans. A 1988, 19, 345–352. [Google Scholar] [CrossRef]
  46. Masahashi, N.; Kawazoe, H.; Takasugi, T.; Izumi, O. Phase-relations in the section Ni3Al-Ni3Fe of the Al-Fe-Ni system. Z. Metallkd. 1987, 78, 788–794. [Google Scholar]
  47. Takasugi, T.; Nagashima, M.; Izumi, O. Strengthening and ductilization of Ni3Si by the addition of Ti elements. Acta Metall. 1990, 38, 747–755. [Google Scholar] [CrossRef]
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Figure 1. Ni3Al–Ni3V pseudo-binary phase diagram adapted from [33], with permission from Elsevier, 2012.
Figure 1. Ni3Al–Ni3V pseudo-binary phase diagram adapted from [33], with permission from Elsevier, 2012.
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Figure 2. (a) Field-emission scanning electron microscopy (FESEM) image and (b) bright-field (BF) transmission electron microscope (TEM) image of the Ni3Al-12V alloy quenched from 1323 K. (c) A selected-area electron diffraction (SAED) pattern taken from the matrix. (d) Schematic illustration of the SAED pattern, viewed from the [001] zone axis of the L12 structure. The fundamental and superlattice reflections from the L12 structure are marked by open and filled circles, respectively.
Figure 2. (a) Field-emission scanning electron microscopy (FESEM) image and (b) bright-field (BF) transmission electron microscope (TEM) image of the Ni3Al-12V alloy quenched from 1323 K. (c) A selected-area electron diffraction (SAED) pattern taken from the matrix. (d) Schematic illustration of the SAED pattern, viewed from the [001] zone axis of the L12 structure. The fundamental and superlattice reflections from the L12 structure are marked by open and filled circles, respectively.
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Figure 3. (a) Bright-field (BF)-TEM image of the Ni3Al-12V alloy aged at 1023 K for 4 h, viewed from the [001] zone axis of the matrix with a L12 structure. (b) SAED pattern taken from the area with a dark elliptical contrast as marked by the dotted circle in (a). (c) Schematic illustration of the SAED pattern viewed from the [100] zone axis for D022 structure [15]. The fundamental and superlattice reflections from the D022 structure are marked by open and filled diamonds, respectively.
Figure 3. (a) Bright-field (BF)-TEM image of the Ni3Al-12V alloy aged at 1023 K for 4 h, viewed from the [001] zone axis of the matrix with a L12 structure. (b) SAED pattern taken from the area with a dark elliptical contrast as marked by the dotted circle in (a). (c) Schematic illustration of the SAED pattern viewed from the [100] zone axis for D022 structure [15]. The fundamental and superlattice reflections from the D022 structure are marked by open and filled diamonds, respectively.
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Figure 4. BF-TEM images of the Ni3Al-12V alloy aged at 1023 K for (a) 16 h (peak-hardened condition) and (b) 48 h, viewed from the [001] zone axis of the matrix with the L12 structure.
Figure 4. BF-TEM images of the Ni3Al-12V alloy aged at 1023 K for (a) 16 h (peak-hardened condition) and (b) 48 h, viewed from the [001] zone axis of the matrix with the L12 structure.
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Figure 5. Schematic illustration of D022 Ni3V precipitates in an L12 Ni3Al matrix grain for the aged Ni3Al-12V alloy specimen. Disk-like shaped Ni3V precipitates are dispersed on {001}m planes with a crystallographic orientation relationship, [001]m//[001]p, (100)m//(100)p between the matrix and precipitates.
Figure 5. Schematic illustration of D022 Ni3V precipitates in an L12 Ni3Al matrix grain for the aged Ni3Al-12V alloy specimen. Disk-like shaped Ni3V precipitates are dispersed on {001}m planes with a crystallographic orientation relationship, [001]m//[001]p, (100)m//(100)p between the matrix and precipitates.
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Figure 6. Variation in Vickers hardness with aging time for the Ni3Al-12V alloy specimens aged at 1073 K, 1123 K, and 1173 K. The measured hardness of the as-quenched specimen is 278 Hv.
Figure 6. Variation in Vickers hardness with aging time for the Ni3Al-12V alloy specimens aged at 1073 K, 1123 K, and 1173 K. The measured hardness of the as-quenched specimen is 278 Hv.
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Figure 7. Nominal stress versus nominal strain curves for the quenched (Q.) Ni3Al-0V and Ni3Al-12V alloy specimens, and peak-aged (P.A.) Ni3Al-12V alloy aged at 1123 K for 16 h.
Figure 7. Nominal stress versus nominal strain curves for the quenched (Q.) Ni3Al-0V and Ni3Al-12V alloy specimens, and peak-aged (P.A.) Ni3Al-12V alloy aged at 1123 K for 16 h.
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Figure 8. Nominal stress versus nominal strain curves for the Ni3Al-12V alloy specimens peak-aged at 1123 K for 16 h, measured at temperatures ranging from 298 K to 1073 K.
Figure 8. Nominal stress versus nominal strain curves for the Ni3Al-12V alloy specimens peak-aged at 1123 K for 16 h, measured at temperatures ranging from 298 K to 1073 K.
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Figure 9. Variations in (a) yield strength (0.2% proof stress), (b) ultimate tensile strength, and (c) fracture strain for the Ni3Al-12V alloy specimens quenched (Q.) and peak-aged (P.A.) at 1123 K for 16 h as a function of the testing temperature.
Figure 9. Variations in (a) yield strength (0.2% proof stress), (b) ultimate tensile strength, and (c) fracture strain for the Ni3Al-12V alloy specimens quenched (Q.) and peak-aged (P.A.) at 1123 K for 16 h as a function of the testing temperature.
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Figure 10. FESEM fractographs for the peak-aged Ni3Al-12V alloy specimens tensile-tested at (a) 298 K and (b) 973 K, together with (c) that for the Ni3Al-0V alloy specimens tensile-tested at 298 K.
Figure 10. FESEM fractographs for the peak-aged Ni3Al-12V alloy specimens tensile-tested at (a) 298 K and (b) 973 K, together with (c) that for the Ni3Al-0V alloy specimens tensile-tested at 298 K.
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MDPI and ACS Style

Semboshi, S.; Sasaki, R.; Kaneno, Y.; Takasugi, T. Age-Induced Precipitation and Hardening Behavior of Ni3Al Intermetallic Alloys Containing Vanadium. Metals 2019, 9, 160. https://doi.org/10.3390/met9020160

AMA Style

Semboshi S, Sasaki R, Kaneno Y, Takasugi T. Age-Induced Precipitation and Hardening Behavior of Ni3Al Intermetallic Alloys Containing Vanadium. Metals. 2019; 9(2):160. https://doi.org/10.3390/met9020160

Chicago/Turabian Style

Semboshi, Satoshi, Ryosuke Sasaki, Yasuyuki Kaneno, and Takayuki Takasugi. 2019. "Age-Induced Precipitation and Hardening Behavior of Ni3Al Intermetallic Alloys Containing Vanadium" Metals 9, no. 2: 160. https://doi.org/10.3390/met9020160

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