Abstract
Shape Memory Alloys (SMAs) are special materials due to their shape recovery behaviors. SMAs remember their original shape after being deformed in their low temperature martensite phase and then heated back to their high temperature austenite phase. Thus, SMAs can be utilized as actuators in aerospace industry. NiTi based SMAs are widely used ones due to their high shape recovery and work output ability against applied load. However, their transformation temperatures (TTs) are lower than 100 ˚C and this limits their application area. There is a strong desire to increase TTs of SMAs for making them suitable candidates for high temperature applications. Nevertheless, as their working temperatures increase with the increase in TTs, the cyclic stability of the alloys starts to decrease due to the decrease in the resistance to plastic deformation via dislocation formation. As the martensite-austenite transformation takes place, dislocations, which are formed with the thermal and/or mechanical cycles pin the martensite/austenite boundary. Therefore, SMA is not able to demonstrate full shape recovery due to plastic deformation, which also leads to the presence of retained martensite. There are several ways to raise TTs of NiTi binary alloys and to provide cyclic stability such as adding ternary element and applying heat treatments. The most promising additional element is Hf due to its lower cost and its effect in increasing the TTs to very high levels. Furthermore, it should be noted that NiTiHf ternary alloys are not only known as high temperature shape memory alloys (HTSMAs) but also high strength alloys.
In this study, Ni50.1Ti19.9Hf30 (at%) was used due to its very high TTs and strength. Although NiTiHf alloys have very good properties as mentioned before, they lose these properties at high temperatures. Therefore, thermo-mechanical heat treatments were applied to very Hf-rich Ni50.1Ti19.9Hf30 (at%) HTSMA to enhance its high temperature, functional and shape memory properties (SMPs). The alloy was first homogenized (H) and then warm rolled (WRed) at 3 different temperatures via following 2 different thickness reductions. Functional fatigue experiments (FFE) were conducted on homogenized and on each warm rolled sample. The effect of rolling temperature together with the percentage of thickness reduction on SMPs such as TTs (Austenite start (As) and finish (Af), martensite start (Ms) and finish (Mf) temperatures), actuation (εact) and irrecoverable strains(εirr) was revealed by comparing the WRed samples with the H one. The hot extruded alloy was homogenized at 1050 ˚C for 2 hours and then the slices, which were cut from the extruded billet, were WRed at 500°C with 2% thickness reduction, at 800°C and 900°C with 10% thickness reduction.
TTs of all samples were measured by Differential Scanning Calorimetry (DSC) to determine the effect of warm rolling. Then FFEs were conducted using dog bone shape tensile specimens. The samples were loaded to 200MPa constant stress level and thermally cycled between 250°C and 700°C. All results, which were gathered from DSC and FFE, were compared.
One of the most promising findings in this study was the effect of warm rolling on the stability of the functional properties of Ni50.1Ti19.9Hf30 (at%) alloy. Actuation strain (εact) values were found to be quite low but very stable throughout the FFE cycles. Moreover, TTs did not decrease significantly with warm rolling process.
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[1] J. Ma, I. Karaman, and R. D. Noebe, “High temperature shape memory alloys,”
International Materials Reviews, vol. 55, no. 5, pp. 257–315, Sep. 2010.
[2] D. J. Hartl and D. C. Lagoudas, “Aerospace applications of shape memory alloys,”
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of
Aerospace Engineering, vol. 221, no. 4, pp. 535–552, Apr. 2007.
[3] J. M. Jani, M. Leary, and A. Subic, “Shape Memory Alloys in Automotive
Applications,” Applied Mechanics and Materials, vol. 663, pp. 248–253, Oct.
2014.
[4] F. el Feninat, G. Laroche, M. Fiset, and D. Mantovani, “Shape Memory Materials
for Biomedical Applications,” Advanced Engineering Materials, vol. 4, no. 3, pp.
91–104, Mar. 2002.
[5] K. Otsuka and X. Ren, “Physical metallurgy of Ti–Ni-based shape memory
alloys,” Progress in Materials Science, vol. 50, no. 5, pp. 511–678, Jul. 2005.
[6] B. Kockar, I. Karaman, J. I. Kim, Y. I. Chumlyakov, J. Sharp, and C.-J. (Mike)
Yu, “Thermomechanical cyclic response of an ultrafine-grained NiTi shape
memory alloy,” Acta Materialia, vol. 56, no. 14, pp. 3630–3646, Aug. 2008.
[7] J. Mohd Jani, M. Leary, A. Subic, and M. A. Gibson, “A review of shape memory
alloy research, applications and opportunities,” Materials & Design (1980-2015),
vol. 56, pp. 1078–1113, Apr. 2014.
[8] H. O. Tugrul, H. H. Saygili, M. S. Velipasaoglu, and B. Kockar, “Comparison of
the transformation behavior of cold rolling with aging and hot extrusion with aging
processed Ni 50.3 Ti 29.7 Hf 20 high temperature shape memory alloy,” Smart
Materials and Structures, vol. 28, no. 10, p. 105029, Oct. 2019.
[9] G. S. Firstov, J. van Humbeeck, and Yu. N. Koval, “High Temperature Shape
Memory Alloys Problems and Prospects,” Journal of Intelligent Material Systems
and Structures, vol. 17, no. 12, pp. 1041–1047, Dec. 2006.
[10] M. Ataei, A. Zarei-Hanzaki, and A. Shamsolhodaei, “Shape memory response and
mechanical properties of warm deformed NiTi intermetallic alloy,” Materials
Science and Engineering: A, vol. 680, pp. 291–296, Jan. 2017.
[11] N. Babacan, M. Bilal, C. Hayrettin, J. Liu, O. Benafan, and I. Karaman, “Effects
of cold and warm rolling on the shape memory response of Ni50Ti30Hf20 hightemperature
shape memory alloy,” Acta Materialia, vol. 157, pp. 228–244, Sep.
2018.
[12] M. Prasher, D. Sen, R. Tewari, P. S. R. Krishna, P. D. Babu, and M. Krishnan,
“Effect of Hf solute addition on the phase transformation behavior and hardness of
a Ni-rich NiTi alloy,” Materials Chemistry and Physics, vol. 247, p. 122890, Jun.
2020.
[13] H. H. Saygili, H. O. Tugrul, and B. Kockar, “Effect of Aging Heat Treatment on
the High Cycle Fatigue Life of Ni50.3Ti29.7Hf20 High-Temperature Shape
Memory Alloy,” Shape Memory and Superelasticity, vol. 5, no. 1, pp. 32–41, Mar.
2019.
[14] Velipasaoglu Mustafa Sefa, “The Determination of The Functional Fatigue Life of
High Temperature Shape Memory Alloys After Cold Rolling Process,” Graduate
School of Science and Engineering of Hacettepe University, Ankara, 2020.
[15] K. Otsuka and X. Ren, “Recent developments in the research of shape memory
alloys,” Intermetallics (Barking), vol. 7, no. 5, pp. 511–528, May 1999.
[16] W. Abuzaid and H. Sehitoglu, “Functional fatigue of Ni50.3Ti25Hf24.7 –
Heterogeneities and evolution of local transformation strains,” Materials Science
and Engineering: A, vol. 696, pp. 482–492, Jun. 2017.
[17] D. C. Lagoudas, Shape Memory Alloys, vol. 1. Boston, MA: Springer US, 2008.
[18] D. J. Hartl and D. C. Lagoudas, “Aerospace applications of shape memory alloys,”
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of
Aerospace Engineering, vol. 221, no. 4, pp. 535–552, Apr. 2007.
[19] W. Abuzaid and H. Sehitoglu, “Functional fatigue of Ni50.3Ti25Hf24.7 –
Heterogeneities and evolution of local transformation strains,” Materials Science
and Engineering: A, vol. 696, pp. 482–492, Jun. 2017.
[20] T. B. Massalski, “Solid-state transformations in copper-based alloys,” Metals
Technology, vol. 7, no. 1, pp. 300–304, Jan. 1980.
[21] R. Dasgupta, “A look into Cu-based shape memory alloys: Present scenario and
future prospects,” Journal of Materials Research, vol. 29, no. 16, pp. 1681–1698,
Aug. 2014.
[22] Saygili Hasan Huseyin, “The Development of a fatigue test machine to investigate
the functional fatigue life of high temperature shape memory alloys and the
determination of the functional fatigue life of these alloys,” Graduate School of
Science and Engineering of Hacettepe University, Ankara, 2018.
[23] T. Maruyama and H. Kubo, “Ferrous (Fe-based) shape memory alloys (SMAs):
properties, processing, and applications,” in Shape Memory and Superelastic
Alloys, Elsevier, 2011, pp. 141–159.
[24] H. E. Karaca et al., “Shape memory behavior of high strength NiTiHfPd
polycrystalline alloys,” Acta Materialia, vol. 61, no. 13, pp. 5036–5049, Aug.
2013.
[25] H. Y. Kim, T. Jinguu, T. Nam, and S. Miyazaki, “Cold workability and shape
memory properties of novel Ti–Ni–Hf–Nb high-temperature shape memory
alloys,” Scripta Materialia, vol. 65, no. 9, pp. 846–849, Nov. 2011.
[26] X. L. Meng, W. Cai, Y. D. Fu, J. X. Zhang, and L. C. Zhao, “Martensite structure
in Ti–Ni–Hf–Cu quaternary alloy ribbons containing (Ti,Hf)2Ni precipitates,”
Acta Materialia, vol. 58, no. 10, pp. 3751–3763, Jun. 2010.
[27] X. L. Meng, W. Cai, K. T. Lau, L. C. Zhao, and L. M. Zhou, “Phase transformation
and microstructure of quaternary TiNiHfCu high temperature shape memory
alloys,” Intermetallics (Barking), vol. 13, no. 2, pp. 197–201, Feb. 2005.
[28] H. E. Karaca et al., “Effects of nanoprecipitation on the shape memory and material
properties of an Ni-rich NiTiHf high temperature shape memory alloy,” Acta
Materialia, vol. 61, no. 19, pp. 7422–7431, Nov. 2013.
[29] D. Golberg et al., “Characteristics of Ti50Pd30Ni20 high-temperature shape
memory alloy,” Intermetallics (Barking), vol. 3, no. 1, pp. 35–46, Jan. 1995,
[30] O. Benafan et al., “Shape memory alloy actuator design: CASMART collaborative
best practices and case studies,” International Journal of Mechanics and Materials
in Design, vol. 10, no. 1, pp. 1–42, Mar. 2014.
[31] E. T. F. Chau, C. M. Friend, D. M. Allen, J. Hora, and J. R. Webster, “A technical
and economic appraisal of shape memory alloys for aerospace applications,”
Materials Science and Engineering: A, vol. 438–440, pp. 589–592, Nov. 2006,
[32] L. McDonald Schetky, “Shape memory alloy applications in space systems,”
Materials & Design, vol. 12, no. 1, pp. 29–32, Feb. 1991.
[33] J. van Humbeeck, “Non-medical applications of shape memory alloys,” Materials
Science and Engineering: A, vol. 273–275, pp. 134–148, Dec. 1999.
[34] A. W. Young, R. W. Wheeler, N. A. Ley, O. Benafan, and M. L. Young,
“Microstructural and Thermomechanical Comparison of Ni-Rich and Ni-Lean
NiTi-20 at. % Hf High Temperature Shape Memory Alloy Wires,” Shape Memory
and Superelasticity, vol. 5, no. 4, pp. 397–406, Dec. 2019.
[35] S. Barbarino, E. I. Saavedra Flores, R. M. Ajaj, I. Dayyani, and M. I. Friswell, “A
review on shape memory alloys with applications to morphing aircraft,” Smart
Materials and Structures, vol. 23, no. 6, p. 063001, Jun. 2014.
[36] R. HOLTZ, “Fatigue thresholds of Ni-Ti alloy near the shape memory transition
temperature,” International Journal of Fatigue, vol. 21, pp. 137–145, Sep. 1999,
[37] N. Simiriotis, M. Fragiadakis, J. F. Rouchon, and M. Braza, “Shape control and
design of aeronautical configurations using shape memory alloy actuators,”
Computers & Structures, vol. 244, p. 106434, Feb. 2021.
[38] C. M. Denowh and D. A. Miller, “Thermomechanical training and characterization
of Ni–Ti–Hf and Ni–Ti–Hf–Cu high temperature shape memory alloys,” Smart
Materials and Structures, vol. 21, no. 6, p. 065020, Jun. 2012.
[39] K. C. Atli, I. Karaman, R. D. Noebe, G. Bigelow, and D. Gaydosh, “Work
production using the two-way shape memory effect in NiTi and a Ni-rich NiTiHf
high-temperature shape memory alloy,” Smart Materials and Structures, vol. 24,
no. 12, p. 125023, Dec. 2015.
[40] B. Amin-Ahmadi, T. Gallmeyer, J. G. Pauza, T. W. Duerig, R. D. Noebe, and A.
P. Stebner, “Effect of a pre-aging treatment on the mechanical behaviors of
Ni50.3Ti49.7−xHfx (x ≤ 9 at. %) Shape memory alloys,” Scripta Materialia, vol.
147, pp. 11–15, Apr. 2018.
[41] M. I. Khan, H. Y. Kim, Y. Namigata, T. Nam, and S. Miyazaki, “Combined effects
of work hardening and precipitation strengthening on the cyclic stability of
TiNiPdCu-based high-temperature shape memory alloys,” Acta Materialia, vol.
61, no. 13, pp. 4797–4810, Aug. 2013.
[42] H. E. Karaca, E. Acar, H. Tobe, and S. M. Saghaian, “NiTiHf-based shape memory
alloys,” Materials Science and Technology, vol. 30, no. 13, pp. 1530–1544, Nov.
2014.
[43] Y. Wang, “The tensile behavior of Ti36Ni49Hf15 high temperature shape memory
alloy,” Scripta Materialia, vol. 40, no. 12, pp. 1327–1331, May 1999.
[44] S. Besseghini, E. Villa, and A. Tuissi, “NiTiHf shape memory alloy: effect of
aging and thermal cycling,” Materials Science and Engineering: A, vol. 273–275,
pp. 390–394, Dec. 1999.
[45] D. R. Angst, P. E. Thoma, and M. Y. Kao, “The Effect of Hafnium Content on the
Transformation Temperatures of Ni 49 Ti 51-x Hf x. Shape Memory Alloys,” Journal
de Physique IV, vol. 05, no. C8, pp. C8-747-C8-752, Dec. 1995.
[46] P. E. T. M. Y. K. and D. R. A. D. Abu Judom, “High transformation temperature
shape memory alloy,” 1992.
[47] M. Frost, B. Benešová, H. Seiner, M. Kružík, P. Šittner, and P. Sedlák,
“Thermomechanical model for NiTi-based shape memory alloys covering
macroscopic localization of martensitic transformation,” International Journal of
Solids and Structures, vol. 221, pp. 117–129, Jun. 2021.
[48] D. C. Lagoudas, D. A. Miller, L. Rong, and P. K. Kumar, “Thermomechanical
fatigue of shape memory alloys,” Smart Materials and Structures, vol. 18, no. 8,
p. 085021, Aug. 2009.
[49] O. W. Bertacchini, D. C. Lagoudas, F. T. Calkins, and J. H. Mabe,
“Thermomechanical cyclic loading and fatigue life characterization of nickel rich
NiTi shape-memory alloy actuators,” Mar. 2008, p. 692916.
[50] H. Hosoda et al., “Cold rolling of B2 intermetallics,” Journal of Alloys and
Compounds, vol. 302, no. 1–2, pp. 266–273, Apr. 2000.
[51] M. E. Mitwally and M. Farag, “Effect of cold work and annealing on the structure
and characteristics of NiTi alloy,” Materials Science and Engineering: A, vol. 519,
no. 1–2, pp. 155–166, Aug. 2009.
[52] N. A. Ley, R. W. Wheeler, O. Benafan, and M. L. Young, “Characterization of
Thermomechanically Processed High-Temperature Ni-Lean NiTi–20 at. % Hf
Shape Memory Wires,” Shape Memory and Superelasticity, vol. 5, no. 4, pp. 476–
485, Dec. 2019.
[53] O. Karakoc, C. Hayrettin, D. Canadinc, and I. Karaman, “Role of applied stress
level on the actuation fatigue behavior of NiTiHf high temperature shape memory
alloys,” Acta Materialia, vol. 153, pp. 156–168, Jul. 2018.
[54] A. Ahadi, E. Rezaei, and A. Karimi Taheri, “Effect of hot rolling on microstructure
and transformation cycling behaviour of equiatomic NiTi shape memory alloy,”
Materials Science and Technology, vol. 28, no. 6, pp. 727–732, Jun. 2012.
[55] O. Akgul, H. O. Tugrul, and B. Kockar, “Effect of the cooling rate on the thermal
and thermomechanical behavior of NiTiHf high-temperature shape memory
alloy,” Journal of Materials Research, vol. 35, no. 12, pp. 1572–1581, Jun. 2020.
