Hot Deformation Behavior of Ti30Ni50Hf20 High-Temperature Shape Memory Alloy
JIANG Muchi1,2, GONG Jishuang3, YANG Xingyuan2, REN Dechun2(), CAI Yusheng2, LI Bingyang4,5, JI Haibin2(), LEI Jiafeng1,2
1 School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China 2 Shi -changxu Advanced Materials Innovation Center, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China 3 School of Aeronautics and Astronautics, Sun Yat-Sen University, Guangzhou 510275, China 4 Advanced Materials and Energy Center, China Academy of Aerospace Science and Innovation, Beijing 100163, China 5 College of Engineering, Peking University, Beijing 100871, China
Cite this article:
JIANG Muchi, GONG Jishuang, YANG Xingyuan, REN Dechun, CAI Yusheng, LI Bingyang, JI Haibin, LEI Jiafeng. Hot Deformation Behavior of Ti30Ni50Hf20 High-Temperature Shape Memory Alloy. Acta Metall Sin, 2025, 61(6): 857-865.
The application of Ti-Ni binary alloy at high temperatures is hindered by its low phase transition temperature. To enhance this transition temperature, researchers have explored the addition of metal Hf to Ti-Ni alloy. However, Ti-Ni-Hf high-temperature shape memory alloy exhibits brittleness and lacks favorable thermal deformation characteristics. Thus, a comprehensive investigation of its thermal deformation behavior is essential. During the hot working process, the material undergoes shape and microstructural changes, which are influenced by various processing factors. Consequently, optimizing processing parameters, including temperature, strain, and strain rate, is crucial for producing defect-free components with the desired microstructure. To optimize the hot working technology, single-pass compression tests on a Gleeble-3800 thermo-simulation machine were conducted and the hot deformation behavior and workability of the high-temperature shape memory alloy Ti30Ni50Hf20 were explored. These tests covered a temperature range of 700-900 oC and a strain rate range of 0.01-10 s-1. Flow stress-strain curves for Ti30Ni50Hf20 under different deformation conditions were generated and the evolution of the alloy's microstructure at varying deformation temperatures under a strain rate of 0.01 s-1, as well as at a deformation temperature of 900 oC with different deformation rates were examined. Utilizing a dynamic material model, a processing diagram was constructed and the impact of process parameters on the alloy's processing performance was analyzed. The results indicate that the recrystallization of Ti30Ni50Hf20 high-temperature shape memory alloy increases with the deformation temperature. This alloy exhibits negative temperature sensitivity and positive strain sensitivity, with flow stress increasing as the strain rate rises and decreasing with higher deformation temperatures. A constitutive equation for Ti30Ni50Hf20 high-temperature shape memory alloy during hot working is established, employing the Arrhenius hot deformation equation. The calculated strain activation energy was determined to be 527.447 kJ/mol. It revealed a consistent match between the theoretical and actual peak stress values. Through the assessment of the hot working diagram, the optimal processing parameters are identified as a deformation temperature in the range of 880-900 oC and a strain rate of 0.01-0.04 s-1.
Fig.1 OM image (a) and DSC curve (b) for as-cast Ti30Ni50Hf20 high-temperature shape memory alloy, and DSC curve for as-cast Ti50Ni50 shape memory alloy (c)
Fig.2 Stress-strain curves of Ti30Ni50Hf20 high-temperature shape memory alloy at different temperatures and strain rates () (a) 700 oC (b) 800 oC (c) 900 oC
Fig.3 Variation curves of peak stress (σp) of Ti30Ni50Hf20 high-temperature shape memory alloy with temperature and
Fig.4 Stress-strain curves of Ti30Ni50Hf20 high-temperature shape memory alloy under different deformation temperatures at strain rates of 0.01 s-1 (a), 0.1 s-1 (b), 1 s-1 (c), and 10 s-1 (d)
Fig.5 Relationships between σp and of Ti30Ni50Hf20 high-temperature shape memory alloy (a) σp-ln (b) lnσp-ln (c) ln[sinh(ασp)]-ln (α—stress level parameter)
Fig.6 Relationship between ln[sinh(ασp)] and 1000 / T of Ti30Ni50Hf20 high-temperature shape memory alloy
Fig.7 Relationship between lnZ and ln[sinh(ασp)] of Ti30Ni50Hf20 high-temperature shape memory alloy (Z—Zener-Hollmon parameter)
Fig.8 Comparisons of measured and calculated peak stresses of Ti30Ni50Hf20 high-temperature shape memory alloy
Fig.9 OM images for Ti30Ni50Hf20 high-temperature shape memory alloy at strain rate of 0.01 s-1 at deformation temperatures of 700 oC (a), 800 oC (b), and 900 oC (c)
Fig.10 OM images for Ti30Ni50Hf20 high-temperature shape memory alloy at deformation temperature of 900 oC under strain rates of 0.1 s-1 (a), 1 s-1 (b), and 10 s-1 (c) (Inset in Fig.10b shows the slip band)
Fig.11 Power dissipation diagram of Ti30Ni50Hf20 high-temperature shape memory alloy
Fig.12 Thermal processing diagram of Ti30Ni50Hf20 high-temperature shape memory alloy
1
Singh S, Karthick S, Palani I A. Design and development of Cu-Al-Ni shape memory alloy coated optical fiber sensor for temperature sensing applications [J]. Vacuum, 2021, 191: 110369
2
Chen F, Qiu P C, Liu Y, et al. Microstructure and mechanical properties of NiTi shape memory alloys by in situ laser directed energy deposition [J]. Acta Metall. Sin., 2023, 59: 180
doi: 10.11900/0412.1961.2022.00425
Es-Souni M, Fischer-Brandies H. Assessing the biocompatibility of NiTi shape memory alloys used for medical applications [J]. Anal. Bioanal. Chem., 2005, 381: 557
pmid: 15660223
4
Abbas A, Hung H Y, Lin P C, et al. Atomic layer deposited TiO2 films on an Equiatomic NiTi shape memory alloy for biomedical applications [J]. J. Alloys Compd., 2021, 886: 161282
5
Ren D C, Zhang H B, Li S J, et al. Properties of Ti-Ni pre-alloyed powder used for electron beam melting [J]. Rare Met. Mater. Eng., 2020, 49: 3218
Liao B, Cao L F, Wu X D, et al. Hot deformation behavior and processing map of 7A55 aluminum alloy in double thermo-mechanical treatment process [J]. Nonferrous Met. Eng., 2021, 11(2): 1
Zhu L Z, Lu S Q, Shu X Y, et al. Hot deformation behavior and constitutive relationships of Ni-40Ti shape memory alloy [J]. Spec. Cast. Nonferrous Alloys, 2016, 36: 425
Zhao Y N, Jiang S Y, Zhang Y Q, et al. Hot deformation behavior and processing map of NiTi shape memory alloy [J]. Appl. Sci. Technol., 2017, 44(1): 76
Karelin R, Komarov V, Cherkasov V, et al. Production, mechanical and functional properties of long-length TiNiHf rods with high-temperature shape memory effect [J]. Materials, 2023, 16: 615
17
Tugrul H O, Akgul O, Kockar B. Creep behavior of 50at%Ni 25at%Ti 25at%Hf high temperature shape memory alloy under constant load [J]. Mater. Today Commun., 2022, 33: 104827
18
Meng X L, Cai W, Zheng Y F, et al. Phase transformation and precipitation in aged Ti-Ni-Hf high-temperature shape memory alloys [J]. Mater. Sci. Eng., 2006, A438-440: 666
19
Chen S H, Wang Q Y, Jiang H C, et al. Effect of δ-ferrite on hot deformation and recrystallization of 316KD austenitic stainless steel for sodium-cooled fast reactor application [J]. Acta Metall. Sin., 2024, 60: 367
Li F L, Fu R, Bai Y R, et al. Effects of initial grain size and strengthening phase on thermal deformation and recrystallization behavior of GH4096 superalloy [J]. Acta Metall. Sin., 2023, 59: 855
doi: 10.11900/0412.1961.2021.00532
Semiatin S L, Seetharaman V, Weiss I. Flow behavior and globularization kinetics during hot working of Ti-6Al-4V with a colony alpha microstructure [J]. Mater. Sci. Eng., 1999, A263: 257
28
Bobbili R, Madhu V. Hot deformation behavior and processing maps of Ti-15Al-12Nb alloy [J]. Rare Met., 2022, 41: 2316
29
Lv B J, Peng J, Wang Y J, et al. Dynamic recrystallization behavior and hot workability of Mg-2.0Zn-0.3Zr-0.9Y alloy by using hot compression test [J]. Mater. Des., 2014, 53: 357
30
Wei L L, Pan Q L, Zhou J, et al. Processing maps and flow instability analysis of Al-Zn-Mg-Cu-Zr alloy [J]. J. Cent. South Univ. (Sci. Technol.), 2013, 44: 1798
