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Determination of phase relations in the Co–Cu–Ti system by the diffusion triple technique

Published online by Cambridge University Press:  03 March 2011

H.S. Liu*
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, People’s Republic of China
Y.M. Wang
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, People’s Republic of China
L.G. Zhang
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, People’s Republic of China
Q. Chen
Affiliation:
Thermo-Calc Software AB, SE – 113 47, Stockholm, Sweden
F. Zheng
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, People’s Republic of China
Z.P. Jin
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, People’s Republic of China
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Two isothermal sections of the Co–Cu–Ti ternary system at 973 and 1123 K were experimentally determined using the diffusion triple technique together with scanning electron microscopy and electron probe microanalysis. The solubility of Cu (substituting Co) in CoTi increased from 22.8 at.% at 973 K to 28.1 at.% at 1123 K while that of Co (substituting Cu) in CuTi decreased from 11.1 to 8.8 at.% accordingly. In addition, the solubility limits of the third element in the binary compounds CoTi2, CuTi2, Cu4Ti3, and Cu3Ti2 were remarkable. Besides the solubility change, we found the Cu2Ti phase was stable at 1123 K but disappeared at 973 K. A ternary compound “m” with a composition range covering Co10Cu57Ti33 was detected at both isothermal sections. An invariant reaction Cu4Ti3 + CoTi ↔ CuTi + m at a temperature between 973 and 1023 K was deduced. Further investigations are necessary to confirm the reactions among Cu, Cu4Ti, Cu2Ti, Cu3Ti2, and “m” between 1023 and 1123 K.

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Articles
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1.Nishizawa, T., Ishida, K.: The Co–Cu (cobalt–copper) system. Bull. Alloy Phase Diagram 5, 161 (1984).CrossRefGoogle Scholar
2.Murray, J.L. The Co-Ti (cobalt-titanium) system, in Phase Diagram of Binary Titanium Alloys, edited by Murray, J.L. (ASM International, Materials Park, OH, 1987), p. 59.Google Scholar
3.Murray, J.L. The Cu–Ti (copper–titanium) system, in Phase Diagram of Binary Titanium Alloys, edited by Murray, J.L. (ASM International, Materials Park, OH, 1987), p. 80.Google Scholar
4.Okamoto, H.: Comment on Ca–Fe (calcium–iron). J. Phase Equilib. 15, 565 (1994).CrossRefGoogle Scholar
5.Pfeifer, H.U., Bhan, S., Schubert, K.: On the constitution of the system titanium-nickel-copper and some quasi-homologous alloys Ti–V–Ni, Ti–Co–Cu, and V–Fe–Ni. J. Less-Common Met. 14, 291 (1968).CrossRefGoogle Scholar
6.Wang, Y.M., Liu, H.S., Chen, Q., Zheng, F., Jin, Z.P.: The isothermal section at 923 K of the Co–Cu–Ti ternary system measured by using diffusion triple. J. Alloys Compd. (2006, in press).Google Scholar
7.Wang, Y.M., Liu, H.S., Zheng, F., Chen, Q., Jin, Z.P.: The 1023 K isothermal section of Co–Cu-Ti ternary system measured by diffusion triple technique. Mater. Sci. Eng., A 431, 184 (2006).CrossRefGoogle Scholar
8.Jin, Z.P.: A study of the range of stability of σ phase in some ternary systems. Scand. J. Metall. 10, 279 (1981).Google Scholar
9.Zhao, J-C., Jin, Z.P.: Determination of phase equilibria in the Ti–Fe–Co system at 900 °C. Z. Metallkde. 81, 247 (1990).Google Scholar
10.Jin, Z.P., Qiu, C.: An experimental study and thermodynamic evaluation of the Fe–Mo–Ti system at 1000 °C. Metall. Mater. Trans. A 24A, 2137 (1993).CrossRefGoogle Scholar
11.Lu, X.G., Cui, Y.W., Jin, Z.P.: Experimental and thermodynamic investigation of the Ni–Al–Mo system. Metall. Mater. Trans. A. 30A, 1785 (1999).CrossRefGoogle Scholar
12.Soffa, W.A., Laughlin, D.E.: High-strength age hardening copper–titanium alloys: Redivivus. Prog. Mater. Sci. 49, 347 (2004).CrossRefGoogle Scholar
13.Eremenko, V.N., Buyanov, Yu.I., Prima, S.B.: Phase diagram of the system titanium-copper. Poroshk. Metall. 20, 494 (1966).Google Scholar
14.Xu, H.H., Du, Y., Huang, B.Y., Liu, S.H.: Phase equilibria of the Cu–Nb–Ti system at 850 °C. J. Alloys Compd. 399, 92 (2005).CrossRefGoogle Scholar
15.Gupta, K.P. The Cu–Ni–Ti system, in Phase Diagrams of Ternary Nickel Alloys Indian Institute of Metals, Calcutta, India, 1990, p. 228.Google Scholar
16.Canale, P., Servant, C.: Thermodynamic assessment of the Cu–Ti system taking into account the new stable phase CuTi3. Z. Metallkde. 93, 273 (2002).CrossRefGoogle Scholar