X-ray diffraction studies of NiTi shape memory alloys

• Autorzy: Lekston Z. , Łągiewka E.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The purpose of this paper is to present the results of the investigations of phase transitions of TiNiCo and Ni-rich NiTi shape memory alloys designed for medical applications. Design/methodology/approach: Temperature X-ray diffraction (TXRD), differential scanning calorimetry (DSC), electrical resistivity (ER) and the temperature shape recovery measurements in three-point bending ASTM 2082-01 tests were used. Findings: It has been found in this work that ageing after solution treatment and annealing below the recrystallization temperature after cold working in the alloys studied create separate reversible B2 ↔ R ↔ B19' transformations. During thermomechanical cycles characteristic temperatures of the reversible B2 ↔ R phase transition remain stable. It was concluded that ageing after solution treatment or recovery during annealing after cold working causes the precipitation process and the changes of the defect structure of the alloys promote transitions with the R-phase contribution. Research limitations/implications: The results of the courses of transformations and their characteristic temperatures obtained by TXRD, DSC and ER techniques have a good correlation. Future TXRD research with the use of automatic rapid recording of diffraction patterns during cooling and heating are necessary. The course of phase transitions of the studied alloys determine their applications. Practical implications: The obtained results can be applied into the practice of processing and thermomechanical treatments of NiTi alloys designed for the production of shape memory medical implants and devices which act under the influence of the human body heat. Presented are the conditions of thermomechanical treatment to obtain a wide temperature range for the R-phase existence in the investigated alloys. Originality/value: The paper presents new results of optimization of the thermal treatment of NiTi shape memory alloys to obtain the reversible B2 ↔ R transformation used to prepare new shape memory implants and medical devices which exhibit shape recovery at a narrow temperature range below the human body temperature. In this paper it was shown that the temperature X-ray diffraction method can be used for the visualization of transformation courses and obtaining characteristic temperatures of transformations.

Słowa kluczowe

EN

X-ray phase analysis; metallic alloys; heat treatment; NiTi shape memory alloys

PL

analiza rentgenowska fazowa; stopy metaliczne; obróbka cieplna

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2007
• Tom: Vol. 28, nr 11
• Strony: 665--672
• Opis fizyczny: Bibliogr. 15 poz., wykr.

Twórcy

autor

Lekston Z.

autor

Łągiewka E.

• Institute of Materials Science, University of Silesia, ul. Bankowa 12, 40-007 Katowice, Poland,

Bibliografia

• [1] A. R. Pelton, D. Stockel, T. W. Duerig, Medical uses of Nitinol, Materials Science Forum 327-328 (2000) 63-70.
• [2] W. Kajzer, M. Kaczmarek, A. Krauze, J. Marciniak, Surface modification and corrosion behavior of Ni-Ti alloy used for urological implants, Journal of Achievements in Materials and Manufacturing Engineering 20 (2007) 525-532.
• [3] R. J. Wasilewski, S. R. Butler, J. E. Hanlon, On the Martensitic Transformation in TiNi, Metals Science Journal 24 (1967) 104-110.
• [4] K. Otsuka, X. Ren, Physical metalurgy of Ti-Ni-based shape memory alloys, Progress in Materials Science 50 (2005) 511-678.
• [5] H. C. Ling, R. Kaplow, Phase Transitions and Shape Memory in NiTi, Metallurgical Transactions 11A (1980) 77-83.
• [6] T. Goryczka, J. Van Humbeck, Characterization of a NiTiCu shape memory alloy produced by powder technology, Journal of Achievements in Materials and Manufacturing Engineering 17 (2006) 65-68.
• [7] J. Uchil, K. P. Mohanchandra, K. K. Mahesh, K. Ganesh Kumara, Thermal and electrical characterization of R-phase dependence on heat-treat temperature in Nitinol, Physica B253 (1998) 83-89.
• [8] H. C. Ling, R. Kaplow, Variation in the Shape Recovery Temperature in Ni-Ti Alloys, Materials Science and Engineering 48 (1981) 241-247.
• [9] J. Khalil Allafi, X. Ren, E. Eggeler, The mechanism of multistage martensitic transformations in aged Ni-rich NiTi shape memory alloys, Acta Materialia 50 (2002) 793-803.
• [10] S. Turenne, S. Prokoshkin, V. Brailovski, N. Sacepe, Mechanical and X-ray Characterization of the Assisted Two-Way Shape Memory Effect in NiTi, Canadian Metallurgical Quartely 39 (2000) 217-224.
• [11] Z. Lekston, H. Morawiec, J. Drugacz, Application of superelastic NiTi wires for mandibular distraction, Materials Science and Engineering A378 (2004) 537-541.
• [12] T. Todoroki, H. Tamura, Effect of Heat Treatment after Cold Working on the Phase Transformation in NiTi Alloy, Transactions Japan Institute of Metals 28 (1987) 83-94.
• [13] M. Pattabi, K. Ramakrishna, K. K. Mahehsh, Effect of thermal cycling on the shape memory transformation behavior of NiTi alloy: Powder X-ray diffraction study, Materials Science and Engineering A 448 (2007) 33-38.
• [14] J. Uchil, F. M. Braz Fernandes, K. K. Mahesh, X-ray diffraction study of the phase transformations in NiTi shape memory alloy, Materials Characterization 58 (2007) 243-248.
• [15] M. Kaczmarek, Corrosion resistance of NiTi alloy in simulated body fluids, Archives of Materials Science and Engineering 28/5 (2007) 269-272.