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The phase relationships in the La–Ti–Sn ternary system at 473 K
Journal of Alloys and Compounds 459 (2008) 174–176
The phase relationships in the La–Ti–Sn ternary system at 473 K Yongzhong Zhan ∗ , Yanfei Xu, Haofeng Xie, Zhengwen Yu, Ying Wang, Yinghong Zhuang Key Laboratory of Nonferrous Metal Materials and New Processing Technology, Ministry of Education, Guangxi University, Nanning, Guangxi 530004, PR China Received 8 April 2007; received in revised form 26 April 2007; accepted 26 April 2007 Available online 29 April 2007
Abstract The isothermal section of the La–Ti–Sn ternary system at 473 K has been investigated mainly by means of X-ray powder diffraction (XRD) with the aid of scanning electron microscope (SEM) and optical microscopy (OM). The binary compound, Ti2 Sn3 , is confirmed and no ternary compounds are found in this work. There are 10 binary compounds in the system, which are La5 Sn3 , La5 Sn4 , LaSn, La3 Sn5 , and LaSn3 , Ti3 Sn, Ti2 Sn, Ti5 Sn3 , Ti6 Sn5 and Ti2 Sn3 . © 2007 Published by Elsevier B.V. Keywords: Metals and alloys; Phase diagrams; X-ray diffraction; Scanning electron microscopy (SEM)
1. Introduction It is well known that titanium and titanium alloys have a lot of practical desirable properties. For example, high hardness and strength, outstanding mechanical properties, corrosion resistance, etc., makes Ti alloys attract more and more attentions. In order to improve the combination properties of Ti alloys and step up their practical applications, complex alloying method is considered to be an important researching direction. As a conventional alloying addition for Ti alloys, Sn can significantly increase strength and corrosion resistance. Suiter [1,2] and Kornilov and Nartova [3] investigated the effect of Sn additives on the mechanical properties of pure titanium and found that significant increase in strength occurred by alloying Ti to 3–6 at.% Sn, at room temperature, as well as, at 400 ◦ C. Rare earth (RE) elements are important additives for developing new structural materials with Al alloys, Ti alloys and Fe alloys [4–7]. There are some studies reporting that the addition of small amount of a rare earth element can improve the microstructures and properties of titanium alloys [5,6]. Our project is to develop polynary cast titanium alloys with high performance, it is essen-
tial to investigate the phase relationship of the La–Ti–Sn ternary system. In Refs. [8–10], the La–Ti phase diagram was reported without compounds. A phase diagram of the La–Sn binary system with seven compounds was reported in Ref. [11]. These binary compounds include La5 Sn3 , La5 Sn4 , La11 Sn10 , LaSn, La2 Sn3 , La3 Sn5 , and LaSn3 . The Ti–Sn binary alloy system has been investigated in Refs. [12–18]. Its phase diagram [14] shows four intermediate phases Ti3 Sn, Ti2 Sn, Ti5 Sn3 and Ti6 Sn5 with high melting points and tight homogeneity ranges. A formerly unknown stable phase Ti2 Sn3 was revealed by Kuper at al. [19]. Later, its crystal has been identified by K¨unnen et al. [20]. Structural data for the intermetallic compounds in the three binary systems are given in Table 1. Up to now, the phase diagram of the La–Ti–Sn ternary system has not been reported. No ternary compound has been found in this system. The purpose of the present work is to investigate experimentally the La–Ti–Sn phase diagram, mainly by assemble an isothermal section at 473 K, so as to provide essential information for the design and fabrication of new-type polynary titanium alloys. 2. Experimental details
∗
Corresponding author. Tel.: +86 771 3272311; fax: +86 771 3233530. E-mail address: [email protected] (Y. Zhan).
0925-8388/$ – see front matter © 2007 Published by Elsevier B.V. doi:10.1016/j.jallcom.2007.04.294
Each sample was prepared to have a total weight of 3 g by weighing appropriate amounts of the pure components (La: 99.9 wt.%, Ti: 99.99 wt.%, Sn:
Y. Zhan et al. / Journal of Alloys and Compounds 459 (2008) 174–176
175
Table 1 Binary crystal structure data of the La–Ti–Sn system Compound
La5 Sn3 La5 Sn4 LaSn La3 Sn5 LaSn3 Ti3 Sn Ti2 Sn Ti5 Sn3 Ti6 Sn5 Ti2 Sn3
Space group
I4/mcm Pnma Cmcm Cmcm ¯ Pm3m P63 /mmc P63 /mmc P63 /mcm P63 /mmc Cmca
Lattice parameters (nm)
Reference
a
b
c
1.2748 0.8448 0.4782(3) 1.035 0.47694(2) 0.5916 0.4653 0.8049(2) 0.922 0.596
– 1.626 1.194(1) 0.829 – – – – – 1.994
0.6344 0.8604 0.4422(3) 1.063 – 0.4764 0.569 0.5454(2) 0.569 0.702
[22] [22] [22] [22] [22] [23] [23] [23] [23] [20]
99.99 wt.%). One hundred and five alloy buttons have been produced by arc melting on a water-cooled copper crucible with a non-consumable tungsten electrode under pure argon atmosphere. Each as-arc-cast button was melted three times and turned around after melting for better homogeneity. For most alloys, the weight loss is less than 1% after melting. The as-cast samples were sealed in an evacuated quartz tube for homogenization treatment and then annealed at different temperatures in order to attain good homogenization. The heat treatment temperature was determined by differential thermal analysis (DTA) or based on previous work of the three binary phase diagrams [8,10,14]. The binary samples that contain more than 75% Sn in the La–Sn system or 45.5% Sn in the Ti–Sn system, as well as the ternary samples with Sn content higher than 60%, were firstly annealed at 773 K for 720 h and then cooled down to 473 K at a rate of 0.15 K/min, then kept at 473 K for 240 h. The other samples were firstly homogenised at 1073 K for 720 h, then cooled down to 473 K at a rate of 0.15 K/min, and finally kept at 473 K for 240 h. Finally, all these annealed buttons were quenched in liquid nitrogen. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive analysis (EDX) were used in the present investigation. Samples for XRD analysis were firstly powdered and then analyzed on a Rigaku D/Max 2500 V diffractometer with Cu K␣ radiation and graphite monochromator operated at 40 kV, 200 mA. The Materials Data Inc. software Jade 5.0 [21] and Powder Diffraction File (PDF release 2002) were used for phase identification. By all these means, the phases and the crystal structures of the alloys in the La–Ti–Sn ternary system were determined.
Fig. 1. XRD pattern of the equilibrated alloy (40 at.% Ti, 60 at.% Sn) indicating the existence of Ti2 Sn3 .
3.1.3. Ti–Sn system In the Ti–Sn system, the phase diagram [16] shows four intermediate phases, namely, Ti3 Sn, Ti2 Sn, Ti5 Sn3 and Ti6 Sn5 . A formerly unknown stable phase Ti2 Sn3 and its crystal structure have been reported [19,20,23–25]. In this work, the XRD pattern of the equilibrated samples containing 40 at.% Ti and 60 at.% Sn clearly indicates the existence of single phase Ti2 Sn3 , as illustrated in Fig. 1. From Fig. 2(a), it can be observed that, at 473 K, there are three phases in the sample with (10 at.%La,10 at.%Ti, 80 at.%Sn), i.e. Sn, LaSn3 and Ti2 Sn3 . As the microstructure of this sample was examined by SEM, three phases were clearly observed, as shown in Fig. 2(b). EDX result indicated that the black phase was LaSn3 , the gray one was Ti2 Sn3 while the white phase was Sn. Combined with the above results, the binary com-
3. Results and discussion 3.1. Binary system 3.1.1. La–Ti system The present work has indicated that no binary compound exists in the La–Ti system, which agrees well with the results of Refs. [8–10]. 3.1.2. La–Sn system According to Ref. [11], seven compounds, i.e. La5 Sn3 , La5 Sn4 , La11 Sn10 , LaSn, La2 Sn3 , La3 Sn5 , and LaSn3 , were found in the La–Sn binary system (Table 1). Except the two compounds La11 Sn10 and La2 Sn3 , the other five of them have been confirmed. Zhuang et al. [22] investigated the isothermal section of the La–Ni–Sn ternary system at 673 K and found that La11 Sn10 and La2 Sn3 do not exist in the La–Sn binary system. In the present work, the phases of La11 Sn10 and La2 Sn3 were not observed either. That is to say, there are five binary compounds La5 Sn3 , La5 Sn4 , LaSn, La3 Sn5 , and LaSn3 in the La–Sn system at 473 K.
Fig. 2. Results of the equilibrated alloy (containing 10 at.% La, 10 at.% Ti and 80 at.% Sn) showing the existence of three phases Sn, LaSn3 and Ti2 Sn3 . (a) XRD pattern and (b) SEM micrograph.
176
Y. Zhan et al. / Journal of Alloys and Compounds 459 (2008) 174–176
4. Conclusion The phase relationships of the La–Ti–Sn ternary system at 473 K have been determined. The existence of a binary compound Ti2 Sn3 was confirmed in the isothermal section. No ternary compound is found in the ternary system. Acknowledgements
Fig. 3. The experimental isothermal section of the La–Ti–Sn ternary system at 473 K.
The authors wish to express thanks to the financial support of the Key Project of China Ministry of Education (207085), the National Natural Science Foundation of China (50601006), the Guangxi Special Fund for Developing Academic Leaders in the New Century (2004218), Guangxi Science Foundation (0640022, 0542011), the Support Program for 100 Young and Middle-aged Disciplinary Leaders in Guangxi Higher Education Institutions (2005-64), the Opening Foundation of Key Laboratory of Nonferrous Materials and Processing Technology (kfjj200501). References
pound Ti2 Sn3 whose atomic ratio is Ti/Sn = 1:1.5 was confirmed in the present isothermal section. Therefore, there are five kinds of binary compounds in Ti–Sn binary system at 473 K, which are Ti3 Sn, Ti2 Sn, Ti5 Sn3 , Ti6 Sn5 and Ti2 Sn3 .
[1] [2] [3] [4] [5]
3.2. Ternary phases In the previous works, no ternary compounds have been reported in this system. It is confirmed in this work that there is no ternary compound in the ternary La–Ti–Sn system at 473 K.
[6] [7] [8] [9]
3.3. Isothermal section The isothermal section of the ternary La–Ti–Sn system at 473 K was determined by XRD, SEM and optical microscopy. The isothermal section, shown in Fig. 3, consists of 13 singlephase regions, 23 binary phase regions and 11 ternary phase regions. Details of the three-phase regions and compositions of the typical alloys are given in Table 2. Table 2 Details of the three-phase regions and compositions of the typical alloys of the La–Ti–Sn at 473 K Phase regions
1 2 3 4 5 6 7 8 9 10 11
Alloy composition (at.%) La
Ti
Sn
0.1 0.1 0.2 0.15 0.3 0.15 0.3 0.25 0.2 0.1 0.4
0.2 0.3 0.2 0.35 0.2 0.45 0.3 0.35 0.5 0.7 0.45
0.7 0.6 0.6 0.5 0.5 0.4 0.4 0.4 0.3 0.2 0.15
Phase composition
[10] [11]
[12] [13] [14] [15] [16] [17] [18]
Sn + LaSn3 + Ti2 Sn3 LaSn3 + Ti2 Sn3 + Ti6 Sn5 Ti6 Sn5 + LaSn3 + La3 Sn5 Ti6 Sn5 + La3 Sn5 + Ti5 Sn3 La3 Sn5 + Ti5 Sn3 + Ti2 Sn La3 Sn5 + Ti2 Sn + LaSn Ti2 Sn + LaSn + Ti3 Sn LaSn + Ti3 Sn + La5 Sn4 La5 Sn3 + Ti3 Sn + La5 Sn4 La5 Sn3 + Ti3 Sn + Ti La5 Sn3 + Ti + La
[19] [20] [21] [22] [23] [24] [25]
J.W. Suiter, J. Inst. Met. 83 (1955) 460–462. J.W. Suiter, J. Inst. Met. 84 (1955) 81–86. I.I. Kornilov, T.T. Nartova, J. Inorg. Chem. 5 (1960) 622–624. S.H. Wang, H.P. Zhou, Y.P. Kang, J. Alloys Compd. 352 (2003) 79–83. Y. Liu, L.F. Chen, W.F. Wei, H.P. Tang, B. Liu, B.Y. Huang, J. Mater. Sci. Technol. 22 (4) (2006) 465–469. K. Xia, W. Li, C. Liu, Scripta Mater. 41 (1) (1999) 67–73. T. Saito, W.Q. Wang, Y. Kamagata, J. Alloys Compd. 402 (2005) 242–245. J.L. Murray, Binary Alloy Phase Diagrams, ASM International, Materials Park, OH, 1987. E.M. Savitskii, G.S. Burkhanov, Z. N. Khim. 2 (11) (1957) 2609–2616 (in Russian); TR, J. Inorg. Chem. 2 (1957) 199–219. E.M. Savitskii, G.S. Burkhanov, J. Less-Common Met. 4 (1962) 301–314. Y.Y. Pan, P. Nash, in: T.B. Massalski, P.R. Subramanian, H. Okamoto, L. Kacprzak (Eds.), Binary Alloy Phase Diagrams, ASM International, Materials Park, OH, 1991. W.L. Finlay, R.I. Jaffee, R.W. Parcel, R.C. Durstein, J. Met. 6 (1954) 25–28. M.K. McQuillan, J. Inst. Met. 84 (1955–1956) 307–310. P. Pietrokowsky, E.P. Frink, Trans. ASM 49 (1957) 339–342. V.V. Glazova, N.N. Kurnakov, Dokl. Akad. Nauk SSSR 134 (1960) 1087 (in Russian). V.N. Eremenko, T.Ya. Velikanova, Z. N. Khim. 7 (1962) 1750 (in Russian). J.H. Vucht, H.A. Brunning, H.C. Donkersloot, A.H. Mesquita, Phillips Res. Rep. 19 (1964) 407. V.D. Savin, Gos. Nauchno-Issled. Proektn. Inst. Redkomet. Prom., Moscow USSR, Zh. Fiz. Khim. 47 (10) (1973) 2527 (in Russian). C. Kuper, W. Peng, A. Pisch, F. Goesmann, R. Schmid-Fetzer, Z. Metallkd. 89 (1998) 855–862. B. K¨unnen, W. Jeitscko, G. Kotzuba, B.D. Mosel, Z. Naturforsch 55b (2000) 425–439. Jade 5.0, XRD Pattern Processing Materials Data Inc., 1999. Y.H. Zhuang, H.X. Deng, J.Q. Liu, Q.R. Yao, J. Alloys Compd. 363 (2004) 223–226. J.W. O’Brien, R.A. Dunlap, J.R. Dahn, J. Alloys Compd. 353 (2003) 60–64. J.W. O’Brien, R.A. Dunlap, J.R. Dahn, J. Alloys Compd. 353 (2003) 65–73. G.P. Vassilev, E.S. Dobrev, J.C. Tedenac, J. Alloys Compd. 407 (2006) 170–175.
The phase relationships in the La–Ti–Sn ternary system at 473 K Yongzhong Zhan ∗ , Yanfei Xu, Haofeng Xie, Zhengwen Yu, Ying Wang, Yinghong Zhuang Key Laboratory of Nonferrous Metal Materials and New Processing Technology, Ministry of Education, Guangxi University, Nanning, Guangxi 530004, PR China Received 8 April 2007; received in revised form 26 April 2007; accepted 26 April 2007 Available online 29 April 2007
Abstract The isothermal section of the La–Ti–Sn ternary system at 473 K has been investigated mainly by means of X-ray powder diffraction (XRD) with the aid of scanning electron microscope (SEM) and optical microscopy (OM). The binary compound, Ti2 Sn3 , is confirmed and no ternary compounds are found in this work. There are 10 binary compounds in the system, which are La5 Sn3 , La5 Sn4 , LaSn, La3 Sn5 , and LaSn3 , Ti3 Sn, Ti2 Sn, Ti5 Sn3 , Ti6 Sn5 and Ti2 Sn3 . © 2007 Published by Elsevier B.V. Keywords: Metals and alloys; Phase diagrams; X-ray diffraction; Scanning electron microscopy (SEM)
1. Introduction It is well known that titanium and titanium alloys have a lot of practical desirable properties. For example, high hardness and strength, outstanding mechanical properties, corrosion resistance, etc., makes Ti alloys attract more and more attentions. In order to improve the combination properties of Ti alloys and step up their practical applications, complex alloying method is considered to be an important researching direction. As a conventional alloying addition for Ti alloys, Sn can significantly increase strength and corrosion resistance. Suiter [1,2] and Kornilov and Nartova [3] investigated the effect of Sn additives on the mechanical properties of pure titanium and found that significant increase in strength occurred by alloying Ti to 3–6 at.% Sn, at room temperature, as well as, at 400 ◦ C. Rare earth (RE) elements are important additives for developing new structural materials with Al alloys, Ti alloys and Fe alloys [4–7]. There are some studies reporting that the addition of small amount of a rare earth element can improve the microstructures and properties of titanium alloys [5,6]. Our project is to develop polynary cast titanium alloys with high performance, it is essen-
tial to investigate the phase relationship of the La–Ti–Sn ternary system. In Refs. [8–10], the La–Ti phase diagram was reported without compounds. A phase diagram of the La–Sn binary system with seven compounds was reported in Ref. [11]. These binary compounds include La5 Sn3 , La5 Sn4 , La11 Sn10 , LaSn, La2 Sn3 , La3 Sn5 , and LaSn3 . The Ti–Sn binary alloy system has been investigated in Refs. [12–18]. Its phase diagram [14] shows four intermediate phases Ti3 Sn, Ti2 Sn, Ti5 Sn3 and Ti6 Sn5 with high melting points and tight homogeneity ranges. A formerly unknown stable phase Ti2 Sn3 was revealed by Kuper at al. [19]. Later, its crystal has been identified by K¨unnen et al. [20]. Structural data for the intermetallic compounds in the three binary systems are given in Table 1. Up to now, the phase diagram of the La–Ti–Sn ternary system has not been reported. No ternary compound has been found in this system. The purpose of the present work is to investigate experimentally the La–Ti–Sn phase diagram, mainly by assemble an isothermal section at 473 K, so as to provide essential information for the design and fabrication of new-type polynary titanium alloys. 2. Experimental details
∗
Corresponding author. Tel.: +86 771 3272311; fax: +86 771 3233530. E-mail address: [email protected] (Y. Zhan).
0925-8388/$ – see front matter © 2007 Published by Elsevier B.V. doi:10.1016/j.jallcom.2007.04.294
Each sample was prepared to have a total weight of 3 g by weighing appropriate amounts of the pure components (La: 99.9 wt.%, Ti: 99.99 wt.%, Sn:
Y. Zhan et al. / Journal of Alloys and Compounds 459 (2008) 174–176
175
Table 1 Binary crystal structure data of the La–Ti–Sn system Compound
La5 Sn3 La5 Sn4 LaSn La3 Sn5 LaSn3 Ti3 Sn Ti2 Sn Ti5 Sn3 Ti6 Sn5 Ti2 Sn3
Space group
I4/mcm Pnma Cmcm Cmcm ¯ Pm3m P63 /mmc P63 /mmc P63 /mcm P63 /mmc Cmca
Lattice parameters (nm)
Reference
a
b
c
1.2748 0.8448 0.4782(3) 1.035 0.47694(2) 0.5916 0.4653 0.8049(2) 0.922 0.596
– 1.626 1.194(1) 0.829 – – – – – 1.994
0.6344 0.8604 0.4422(3) 1.063 – 0.4764 0.569 0.5454(2) 0.569 0.702
[22] [22] [22] [22] [22] [23] [23] [23] [23] [20]
99.99 wt.%). One hundred and five alloy buttons have been produced by arc melting on a water-cooled copper crucible with a non-consumable tungsten electrode under pure argon atmosphere. Each as-arc-cast button was melted three times and turned around after melting for better homogeneity. For most alloys, the weight loss is less than 1% after melting. The as-cast samples were sealed in an evacuated quartz tube for homogenization treatment and then annealed at different temperatures in order to attain good homogenization. The heat treatment temperature was determined by differential thermal analysis (DTA) or based on previous work of the three binary phase diagrams [8,10,14]. The binary samples that contain more than 75% Sn in the La–Sn system or 45.5% Sn in the Ti–Sn system, as well as the ternary samples with Sn content higher than 60%, were firstly annealed at 773 K for 720 h and then cooled down to 473 K at a rate of 0.15 K/min, then kept at 473 K for 240 h. The other samples were firstly homogenised at 1073 K for 720 h, then cooled down to 473 K at a rate of 0.15 K/min, and finally kept at 473 K for 240 h. Finally, all these annealed buttons were quenched in liquid nitrogen. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive analysis (EDX) were used in the present investigation. Samples for XRD analysis were firstly powdered and then analyzed on a Rigaku D/Max 2500 V diffractometer with Cu K␣ radiation and graphite monochromator operated at 40 kV, 200 mA. The Materials Data Inc. software Jade 5.0 [21] and Powder Diffraction File (PDF release 2002) were used for phase identification. By all these means, the phases and the crystal structures of the alloys in the La–Ti–Sn ternary system were determined.
Fig. 1. XRD pattern of the equilibrated alloy (40 at.% Ti, 60 at.% Sn) indicating the existence of Ti2 Sn3 .
3.1.3. Ti–Sn system In the Ti–Sn system, the phase diagram [16] shows four intermediate phases, namely, Ti3 Sn, Ti2 Sn, Ti5 Sn3 and Ti6 Sn5 . A formerly unknown stable phase Ti2 Sn3 and its crystal structure have been reported [19,20,23–25]. In this work, the XRD pattern of the equilibrated samples containing 40 at.% Ti and 60 at.% Sn clearly indicates the existence of single phase Ti2 Sn3 , as illustrated in Fig. 1. From Fig. 2(a), it can be observed that, at 473 K, there are three phases in the sample with (10 at.%La,10 at.%Ti, 80 at.%Sn), i.e. Sn, LaSn3 and Ti2 Sn3 . As the microstructure of this sample was examined by SEM, three phases were clearly observed, as shown in Fig. 2(b). EDX result indicated that the black phase was LaSn3 , the gray one was Ti2 Sn3 while the white phase was Sn. Combined with the above results, the binary com-
3. Results and discussion 3.1. Binary system 3.1.1. La–Ti system The present work has indicated that no binary compound exists in the La–Ti system, which agrees well with the results of Refs. [8–10]. 3.1.2. La–Sn system According to Ref. [11], seven compounds, i.e. La5 Sn3 , La5 Sn4 , La11 Sn10 , LaSn, La2 Sn3 , La3 Sn5 , and LaSn3 , were found in the La–Sn binary system (Table 1). Except the two compounds La11 Sn10 and La2 Sn3 , the other five of them have been confirmed. Zhuang et al. [22] investigated the isothermal section of the La–Ni–Sn ternary system at 673 K and found that La11 Sn10 and La2 Sn3 do not exist in the La–Sn binary system. In the present work, the phases of La11 Sn10 and La2 Sn3 were not observed either. That is to say, there are five binary compounds La5 Sn3 , La5 Sn4 , LaSn, La3 Sn5 , and LaSn3 in the La–Sn system at 473 K.
Fig. 2. Results of the equilibrated alloy (containing 10 at.% La, 10 at.% Ti and 80 at.% Sn) showing the existence of three phases Sn, LaSn3 and Ti2 Sn3 . (a) XRD pattern and (b) SEM micrograph.
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Y. Zhan et al. / Journal of Alloys and Compounds 459 (2008) 174–176
4. Conclusion The phase relationships of the La–Ti–Sn ternary system at 473 K have been determined. The existence of a binary compound Ti2 Sn3 was confirmed in the isothermal section. No ternary compound is found in the ternary system. Acknowledgements
Fig. 3. The experimental isothermal section of the La–Ti–Sn ternary system at 473 K.
The authors wish to express thanks to the financial support of the Key Project of China Ministry of Education (207085), the National Natural Science Foundation of China (50601006), the Guangxi Special Fund for Developing Academic Leaders in the New Century (2004218), Guangxi Science Foundation (0640022, 0542011), the Support Program for 100 Young and Middle-aged Disciplinary Leaders in Guangxi Higher Education Institutions (2005-64), the Opening Foundation of Key Laboratory of Nonferrous Materials and Processing Technology (kfjj200501). References
pound Ti2 Sn3 whose atomic ratio is Ti/Sn = 1:1.5 was confirmed in the present isothermal section. Therefore, there are five kinds of binary compounds in Ti–Sn binary system at 473 K, which are Ti3 Sn, Ti2 Sn, Ti5 Sn3 , Ti6 Sn5 and Ti2 Sn3 .
[1] [2] [3] [4] [5]
3.2. Ternary phases In the previous works, no ternary compounds have been reported in this system. It is confirmed in this work that there is no ternary compound in the ternary La–Ti–Sn system at 473 K.
[6] [7] [8] [9]
3.3. Isothermal section The isothermal section of the ternary La–Ti–Sn system at 473 K was determined by XRD, SEM and optical microscopy. The isothermal section, shown in Fig. 3, consists of 13 singlephase regions, 23 binary phase regions and 11 ternary phase regions. Details of the three-phase regions and compositions of the typical alloys are given in Table 2. Table 2 Details of the three-phase regions and compositions of the typical alloys of the La–Ti–Sn at 473 K Phase regions
1 2 3 4 5 6 7 8 9 10 11
Alloy composition (at.%) La
Ti
Sn
0.1 0.1 0.2 0.15 0.3 0.15 0.3 0.25 0.2 0.1 0.4
0.2 0.3 0.2 0.35 0.2 0.45 0.3 0.35 0.5 0.7 0.45
0.7 0.6 0.6 0.5 0.5 0.4 0.4 0.4 0.3 0.2 0.15
Phase composition
[10] [11]
[12] [13] [14] [15] [16] [17] [18]
Sn + LaSn3 + Ti2 Sn3 LaSn3 + Ti2 Sn3 + Ti6 Sn5 Ti6 Sn5 + LaSn3 + La3 Sn5 Ti6 Sn5 + La3 Sn5 + Ti5 Sn3 La3 Sn5 + Ti5 Sn3 + Ti2 Sn La3 Sn5 + Ti2 Sn + LaSn Ti2 Sn + LaSn + Ti3 Sn LaSn + Ti3 Sn + La5 Sn4 La5 Sn3 + Ti3 Sn + La5 Sn4 La5 Sn3 + Ti3 Sn + Ti La5 Sn3 + Ti + La
[19] [20] [21] [22] [23] [24] [25]
J.W. Suiter, J. Inst. Met. 83 (1955) 460–462. J.W. Suiter, J. Inst. Met. 84 (1955) 81–86. I.I. Kornilov, T.T. Nartova, J. Inorg. Chem. 5 (1960) 622–624. S.H. Wang, H.P. Zhou, Y.P. Kang, J. Alloys Compd. 352 (2003) 79–83. Y. Liu, L.F. Chen, W.F. Wei, H.P. Tang, B. Liu, B.Y. Huang, J. Mater. Sci. Technol. 22 (4) (2006) 465–469. K. Xia, W. Li, C. Liu, Scripta Mater. 41 (1) (1999) 67–73. T. Saito, W.Q. Wang, Y. Kamagata, J. Alloys Compd. 402 (2005) 242–245. J.L. Murray, Binary Alloy Phase Diagrams, ASM International, Materials Park, OH, 1987. E.M. Savitskii, G.S. Burkhanov, Z. N. Khim. 2 (11) (1957) 2609–2616 (in Russian); TR, J. Inorg. Chem. 2 (1957) 199–219. E.M. Savitskii, G.S. Burkhanov, J. Less-Common Met. 4 (1962) 301–314. Y.Y. Pan, P. Nash, in: T.B. Massalski, P.R. Subramanian, H. Okamoto, L. Kacprzak (Eds.), Binary Alloy Phase Diagrams, ASM International, Materials Park, OH, 1991. W.L. Finlay, R.I. Jaffee, R.W. Parcel, R.C. Durstein, J. Met. 6 (1954) 25–28. M.K. McQuillan, J. Inst. Met. 84 (1955–1956) 307–310. P. Pietrokowsky, E.P. Frink, Trans. ASM 49 (1957) 339–342. V.V. Glazova, N.N. Kurnakov, Dokl. Akad. Nauk SSSR 134 (1960) 1087 (in Russian). V.N. Eremenko, T.Ya. Velikanova, Z. N. Khim. 7 (1962) 1750 (in Russian). J.H. Vucht, H.A. Brunning, H.C. Donkersloot, A.H. Mesquita, Phillips Res. Rep. 19 (1964) 407. V.D. Savin, Gos. Nauchno-Issled. Proektn. Inst. Redkomet. Prom., Moscow USSR, Zh. Fiz. Khim. 47 (10) (1973) 2527 (in Russian). C. Kuper, W. Peng, A. Pisch, F. Goesmann, R. Schmid-Fetzer, Z. Metallkd. 89 (1998) 855–862. B. K¨unnen, W. Jeitscko, G. Kotzuba, B.D. Mosel, Z. Naturforsch 55b (2000) 425–439. Jade 5.0, XRD Pattern Processing Materials Data Inc., 1999. Y.H. Zhuang, H.X. Deng, J.Q. Liu, Q.R. Yao, J. Alloys Compd. 363 (2004) 223–226. J.W. O’Brien, R.A. Dunlap, J.R. Dahn, J. Alloys Compd. 353 (2003) 60–64. J.W. O’Brien, R.A. Dunlap, J.R. Dahn, J. Alloys Compd. 353 (2003) 65–73. G.P. Vassilev, E.S. Dobrev, J.C. Tedenac, J. Alloys Compd. 407 (2006) 170–175.