Skip to main content Accessibility help

Effect of a fourth alloying element on the microstructure and mechanical properties of Cu–Al–Ni shape memory alloys

  • Safaa N. Saud (a1), Esah Hamzah (a1), Tuty Abubakar (a1), Mustafa K. Ibrahim (a1) and Abdollah Bahador (a1)...


The present investigation aims to enhance the mechanical properties and shape memory characteristics of Cu–Ni–Al shape memory alloys (SMAs) by alloying additional elements. These additions were found to control the phase morphology and grain size, along with the formation of different volume fractions, sizes, and distributions of precipitates. The features of the precipitates were mainly dependent on the type of alloying element. It was found that a Co (1.14 wt%) alloy gave the best overall improvement in terms of the transformation temperatures, ductility, and shape memory recovery. These improvements were mainly due to the exceptionally high presence of the γ2 phase in the microstructures of the modified alloy. The results of the current investigation were analyzed and compared to those of previous studies related to Cu–Al–Ni SMAs.


Corresponding author

a) Address all correspondence to this author. e-mail:


Hide All
1. Gandhi, V. and Thompson, B.S.: Smart Materials and Structures (Springer, London, 1992).
2. Otsuka, K. and Wayman, C.M.: Shape Memory Materials (Cambridge University Press, Cambridge, 1999). Reprint, illustrated ed.
3. Olson, G. and Cohen, M.: Stress-assisted isothermal martensitic transformation: Application to TRIP steels. Metall. Trans. A 13(11), 1907 (1982).
4. Fremond, M. and Miyazaki, S.: Shape Memory Alloys (Springer-Verlag, New York, 1996).
5. Kumar, P. and Lagoudas, D.: Introduction to Shape Memory Alloys (Springer, Texas, 2008).
6. Nishiyama, Z., Fine, M.E., and Wayman, C.M.: Martensitic Transformation (Academic Press, New York, 1978).
7. Davis, J.R.: Copper and Copper Alloys (ASM International, New York, 2001).
8. Porter, D.A., Easterling, K.E., and Sherif, M.: Phase Transformations in Metals and Alloys (CRC press, Boca Raton, FL, 2011). (Revised reprint).
9. Otsuka, K. and Ren, X.: Physical metallurgy of Ti–Ni-based shape memory alloys. Prog. Mater. Sci. 50(5), 511 (2005).
10. Lagoudas, D.C.: Shape Memory Alloys: Modeling and Engineering Applications (Springer, New York, 2008).
11. San Juan, J., , M., and Schuh, C.: Superelastic cycling of Cu–Al–Ni shape memory alloy micropillars. Acta Mater. 60(10), 4093 (2012).
12. Saud, S., Hamzah, E., Abubakar, T., and Bakhsheshi-Rad, H.R.: Thermal aging behavior in Cu–Al–Ni–xCo shape memory alloys. J. Therm. Anal. Calorim. 119(2), 1273 (2015).
13. Saud, S., Hamzah, E., Abubakar, T., Bakhsheshi-Rad, H.R., Zamri, M., and Tanemura, M.: Effects of Mn additions on the structure, mechanical properties, and corrosion behavior of Cu–Al–Ni shape memory alloys. J. Mater. Eng. Perform. 10, 36203629 (2014).
14. Karagoz, Z. and Canbay, C.A.: Relationship between transformation temperatures and alloying elements in Cu–Al–Ni shape memory alloys. J. Therm. Anal. Calorim. 114(3), 1069 (2013).
15. Ibarra, A., Juan, J.S., Bocanegra, E.H., and , M.L.: Thermo-mechanical characterization of Cu–Al–Ni shape memory alloys elaborated by powder metallurgy. Mater. Sci. Eng., A 438440, 782 (2006).
16. Recarte, V., Pérez-Landazábal, J.I., , M.L., and San Juan, J.: Study by resonant ultrasound spectroscopy of the elastic constants of the β phase in Cu–Al–Ni shape memory alloys. Mater. Sci. Eng., A 370(1–2), 488 (2004).
17. Font, J., Cesari, E., Muntasell, J., and Pons, J.: Thermomechanical cycling in Cu–Al–Ni-based melt-spun shape-memory ribbons. Mater. Sci. Eng., A 354(1–2), 207 (2003).
18. Pérez-Landazábal, J.I., Recarte, V., Sánchez-Alarcos, V., , M.L., and Juan, J.S.: Study of the stability and decomposition process of the β phase in Cu–Al–Ni shape memory alloys. Mater. Sci. Eng., A 438440, 734 (2006).
19. Tadaki, T.: Cu-based shape memory alloys. In Shape Memory Materials. (Cambridge University Press, Cambridge, UK, 1998); p. 97.
20. Miyazaki, S., Kawai, T., and Otsuka, K.: Study of fracture in Cu–Al–Ni shape memory bicrystals. J. Phys. Colloques 43(C4), C4-813 (1982).
21. Horikawa, H., Ichinose, S., Morii, K., Miyazaki, S., and Otsuka, K.: Orientation dependence of β1 → β1′ stress-induced martensitic transformation in a Cu–AI–Ni alloy. Metall. Trans. A 19(4), 915 (1988).
22. Schwartz, M.: Smart Materials (CRC Press, Boca Raton, FL, 2008).
23. Otsuka, K., Sakamoto, H., and Shimizu, K.: Successive stress-induced martensitic transformations and associated transformation pseudoelasticity in Cu–Al–Ni alloys. Acta Metall. 27(4), 585 (1979).
24. Sampath, V.: Studies on the effect of grain refinement and thermal processing on shape memory characteristics of Cu–Al–Ni alloys. Smart Mater. Struct. 14(5), S253 (2005).
25. Sugimoto, K., Kamei, K., Matsumoto, H., Komatsu, S., Akamatsu, K., and Sugimoto, T.: Grain-refinement and the related phenomena in quaternary Cu–Al–Ni–Ti shape memory alloys. J. Phys. Colloques 43(C4), C4-761 (1982).
26. Sutou, Y., Omori, T., Kainuma, R., Ishida, K., and Ono, N.: Enhancement of superelasticity in Cu–Al–Mn–Ni shape-memory alloys by texture control. Metall. Mater. Trans. A 33(9), 2817 (2002).
27. Hondros, E. and Seah, M.: Segregation to interfaces. Int. Met. Rev. 22(1), 262 (1977).
28. Stein, D., Johnson, W., White, C., Chadwick, G., and Smith, D.: Grain Boundary Structure and Properties (Academic Press, New York, 1976).
29. Morris, M.A. and Gunter, S.: Effect of heat treatment and thermal cycling on transformation temperatures of ductile Cu–Al–Ni–Mn–B alloys. Scr. Metall. Mater. 26(11), 1663 (1992).
30. Sarı, U. and Kırındı, T.: Effects of deformation on microstructure and mechanical properties of a Cu–Al–Ni shape memory alloy. Mater. Charact. 59(7), 920 (2008).
31. Yildiz, K. and Kok, M.: Study of martensite transformation and microstructural evolution of Cu–Al–Ni–Fe shape memory alloys. J. Therm. Anal. Calorim. 115(2), 1509 (2014).
32. Sutou, Y., Omori, T., Yamauchi, K., Ono, N., Kainuma, R., and Ishida, K.: Effect of grain size and texture on pseudoelasticity in Cu–Al–Mn-based shape memory wire. Acta Mater. 53(15), 4121 (2005).
33. Sarı, U. and Aksoy, İ.: Electron microscopy study of 2H and 18R martensites in Cu–11.92wt% Al–3.78wt% Ni shape memory alloy. J. Alloys Compd. 417(1–2), 138 (2006).
34. Sari, U.: Influences of 2.5wt% Mn addition on the microstructure and mechanical properties of Cu–Al–Ni shape memory alloys. Int. J. Miner., Metall. Mater. 17(2), 192 (2010).
35. Chang, S.H.: Influence of chemical composition on the damping characteristics of Cu–Al–Ni shape memory alloys. Mater. Chem. Phys. 125(3), 358 (2011).
36. Van Humbeeck, J., Chandrasekaran, M., and Stalmans, R.: Copper-based shape memory alloys and the martensitic transformation. Proc. Int. Conf. Martensitic Transform. 25, 1015 (1993).
37. Van Humbeeck, J. and Stalmans, R.: Shape Memory Alloys, Types and Functionalities (John Wiley and Sons, New York, NY, 2002).
38. Aydogdu, Y., Aydogdu, A., and Adiguzel, O.: Self-accommodating martensite plate variants in shape memory CuAlNi alloys. J. Mater. Process. Technol. 123, 498 (2002).
39. Friend, C.M.: The effect of aluminium content on the martensite phase stabilities in metastable CuAlNi alloys. Scr. Metall. 23(10), 1817 (1989).
40. Saud, S., Hamzah, E., Abubakar, T., Zamri, M., and Tanemura, M.: Influence of Ti additions on the martensitic phase transformation and mechanical properties of Cu–Al–Ni shape memory alloys. J. Therm. Anal. Calorim. 118(1), 111122 (2014).
41. Lovey, F. and Cesari, E.: On the microstructural characteristics of non-equilibrium γ precipitates in Cu–Zn–Al alloys. Mater. Sci. Eng., A 129(1), 127 (1990).
42. Hurtado, I., Ratchev, P., Van Humbeeck, J., and Delaey, L.: A fundamental study of the X-phase preciptation in Cu–Al–Ni–Ti-(Mn) shape memory alloys. Acta Mater. 44, 3299 (1995).
43. Lee, J.S. and Wayman, C.M.: Grain refinement of a Cu–Al–Ni shape memory alloy by Ti and Zr additions. Trans. Jpn. Inst. Met. 27(8), 584 (1986).
44. Aydogdu, A., Aydogdu, Y., and Adigüzel, O.: Improvement of hardness and microstructures by ageing in shape memory CuAlNi alloys. J. Phys. IV France 07(C5), C5-311 (1997).
45. Gama, J., Dantas, C., Quadros, N., Ferreira, R., and Yadava, Y.: Microstructure-mechanical property relationship to copper alloys with shape memory during thermomechanical treatments. Metall. Mater. Trans. A. 37(1), 77 (2006).
46. Xuan, Q., Bohong, J., and Hsu, T.Y.: The effect of martensite ordering on shape memory effect in a copper–zinc–aluminium alloy. Mater. Sci. Eng. 93, 205 (1987).
47. Salzbrenner, R.J. and Cohen, M.: On the thermodynamics of thermoelastic martensitic transformations. Acta Metall. 27(5), 739 (1979).
48. Adigüzel, O.: Martensite ordering and stabilization in copper based shape memory alloys. Mater. Res. Bull. 30(6), 755 (1995).
49. Balo, Ş.N. and Sel, N.: Effects of thermal aging on transformation temperatures and some physical parameters of Cu–13.5wt.%Al–4wt.%Ni shape memory alloy. Thermochim. Acta 536, 1 (2012).
50. Yang, G., LEE, J., and Jang, W.: Effect of grain refinement on phase transformation behavior and mechanical properties of Cu-based alloy. Trans. Nonferrous Met. Soc. China 19(4), 979 (2009).
51. Cullity, B.D. and Stock, S.R.: Elements of X-ray Diffraction (Prentice Hall, Boston, MA, 2001).
52. Patterson, A.L.: The scherrer formula for X-ray particle size determination. Phys. Rev. 56(10), 978 (1939).
53. Recarte, V., Pérez-Sáez, R., Bocanegra, E., , M., and San Juan, J.: Dependence of the martensitic transformation characteristics on concentration in Cu–Al–Ni shape memory alloys. Mater. Sci. Eng., A 273, 380 (1999).
54. Dutkiewicz, J., Czeppe, T., and Morgiel, J.: Effect of titanium on structure and martensic transformation in rapidly solidified Cu–Al–Ni–Mn–Ti alloys. Mater. Sci. Eng., A 273, 703 (1999).
55. Manjeri, R.M.: Low Temperature and Reduced Length Scale Behavior of Shape Memory and Superelastic NiTi and NiTiFe Alloys (University of Central Florida, Orlando, Florida, 2009).
56. Pons, J. and Cesari, E.: Interaction between γ-phase precipitates and martensite in Cu–Zn–Al alloys. Mater. Struct. 6(2), 115 (1999).
57. Pons, J. and Portier, R.: Accommodation of γ-phase precipitates in Cu–Zn–Al shape memory alloys studied by high resolution electron microscopy. Acta Mater. 45(5), 2109 (1997).
58. Kireeva, I., Picornell, C., Pons, J., Kretinina, I., Chumlyakov, Y.I., and Cesari, E.: Effect of oriented γ′ precipitates on shape memory effect and superelasticity in Co–Ni–Ga single crystals. Acta Mater. 68, 127 (2014).
59. Tatar, C.: Gamma irradiation-induced evolution of the transformation temperatures and thermodynamic parameters in a CuZnAl shape memory alloy. Thermochim. Acta 437, 121 (2005).
60. Ortín, J. and Planes, A.: Thermodynamics of thermoelastic martensitic transformations. Acta Metall. 37(5), 1433 (1989).
61. Lojen, G., Anžel, I., Kneissl, A., Križman, A., Unterweger, E., Kosec, B., and Bizjak, M.: Microstructure of rapidly solidified Cu–Al–Ni shape memory alloy ribbons. J. Mater. Process. Technol. 162163, 220 (2005).
62. Miyazaki, S., Otsuka, K., Sakamoto, H., and Shimizu, K.: Study of fracture in Cu–Al–Ni shape memory bicrystals. Trans. Jpn. Inst. Met. 22, 244 (1981).
63. Husain, S.W. and Clapp, P.C.: Grain boundary embrittlement in Cu–AI–Ni β phase alloys. J. Mater. Sci. 22, 2351 (1987).
64. Lee, J.S. and Wayman, C.M.: Grain refinement of Cu–Zn–Al shape memory alloys. Metallography 19(4), 401 (1986).
65. Sure, G.N. and Brown, L.C.: The mechanical properties of grain refined β- Cu–Al–Ni strain-memory alloys. Metall. Trans. A 15, 1613 (1984).
66. Bhattacharya, S., Bhuniya, A., and Banerjee, M.K.: Influence of minor additions on characteristics of CuAlNi alloy. Mater. Sci. Technol. 9(8), 654 (1993).
67. Adachi, K., Hamada, Y., and Tagawa, Y.: Crystal structure of the X-phase in grain-refined Cu–Al–Ni–Ti shape memory alloys. Scr. Metall. 21(4), 453 (1987).
68. Kim, J., Roh, D., Lee, E., and Kim, Y.: Effects on microstructure and tensile properties of a zirconium addition to a Cu–Al–Ni shape memory alloy. Metall. Mater. Trans. A 21(2), 741 (1990).
69. Morris, M.A. and Lipe, T.: Microstructural influence of Mn additions on thermoelastic and pseudoelastic properties of Cu–Al–Ni alloys. Acta Metall. Mater. 42(5), 1583 (1994).
70. Gao, Y., Zhu, M., and Lai, J.K.L.: Microstructure characterization and effect of thermal cycling and ageing on vanadium-doped Cu–Al–Ni–Mn high-temperature shape memory alloy. J. Mater. Sci. 33(14), 3579 (1998).
71. Adachi, K., Shoji, K., and Hamada, Y.: Formation of (X) phases and origin of grain refinement effect in Cu–Al–Ni shape memory alloys added with titamium. ISIJ Int. 29(5), 378 (1989).
72. Vajpai, S.K., Dube, R.K., and Sangal, S.: Microstructure and properties of Cu–Al–Ni shape memory alloy strips prepared via hot densification rolling of argon atomized powder performs. Mater. Sci. Eng., A 529(1), 378 (2011).
73. Zhu, M., Ye, X., Li, C., Song, G., and Zhai, Q.: Preparation of single crystal CuAlNiBe SMA and its performances. J. Alloys Compd. 478(1), 404410 (2009).
74. Roh, D.W., Kim, J.W., Cho, T.J., and Kim, Y.G.: Tensile properties and microstructure of microalloyed Cu–Al–Ni–X shape memory alloys. Mater. Sci. Eng., A 136, 17 (1991).
75. Khan, A. and Delaey, L.: The effect of grain size on the strength of Cu–Al beta'-martensite. Z. Metallkd. 60(12), 949 (1969).
76. Motoyasu, G., Kaneko, M., Soda, H., and McLean, A.: Continuously cast Cu–Al–Ni shape memory wires with a unidirectional morphology. Metall. Mater. Trans., A 32(3), 585 (2001).
77. Yang, N., Laird, C., and Pope, D.P.: The cyclic stress-strain response of polycrystalline, pseudoelastic Cu-14.5 wt pct Al-3 wt pct Ni alloy. Metall. Trans. A 8(6), 955 (1977).
78. Funakubo, H.: Shape Memory Alloys (CRC Press LLC, Boca Raton, FL, 1987).
79. Husain, S. and Clapp, P.: The intergranular embrittlement of Cu–AI–Ni β-phase alloys. J. Mater. Sci. 22(7), 2351 (1987).
80. Bhattacharya, K.: Microstructure of Martensite: Why it Forms and how it Gives Rise to the Shape-memory Effect (OUP, Oxford, 2003).
81. Churchill, C.B., Shaw, J.A., and Iadicola, M.A.: Tips and tricks for characterizing shape memory alloy wire: Part 3-localization and propagation phenomena. Exp. Tech. 33(5), 70 (2009).


Related content

Powered by UNSILO

Effect of a fourth alloying element on the microstructure and mechanical properties of Cu–Al–Ni shape memory alloys

  • Safaa N. Saud (a1), Esah Hamzah (a1), Tuty Abubakar (a1), Mustafa K. Ibrahim (a1) and Abdollah Bahador (a1)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.