Partner: S.P. Gadaj


Recent publications
1.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Luckner J., Tobushi H., Martensite and reverse transformation during simple shear of niti shape memory alloy, STRAIN, ISSN: 0039-2103, Vol.45, pp.93-100, 2009
2.Dutkiewicz J.M., Maziarz W., Czeppe T., Lityńska L., Nowacki W.K., Gadaj S.P., Luckner J., Pieczyska E.A., Powder metallurgy technology of niti shape memory alloy, JOURNAL DE PHYSIQUE IV, ISSN: 1155-4339, DOI: 10.1140/epjst/e2008-00654-6, Vol.158, pp.59-65, 2008
Abstract:

Powder metallurgy technology was elaborated for consolidation of shape memory NiTi powders. The shape memory alloy was compacted from the prealloyed powder delivered by Memry SA. The powder shows Ms = 10°C and As = -34°C as results from DSC measurements. The samples were hot pressed in the as delivered spherical particle's state. The hot compaction was performed in a specially constructed vacuum press, at temperature of 680°C and pressure of 400 MPa. The alloy powder was encapsulated in copper capsules prior to hot pressing to avoid oxidation or carbides formation. The alloy after hot vacuum compaction at 680°C (i.e. within the B2 NiTi stability range) has shown similar transformation range as the powder. The porosity of samples compacted in the as delivered state was only 1%. The samples tested in compression up to ε = 0.06 have shown partial superelastic effect due to martensitic reversible transformation which started at the stress above 300 MPa and returned back to ε = 0.015 after unloading. They have shown also a high ultimate compression strength of 1600 MPa. Measurements of the samples temperature changes during the process allowed to detect the temperature increase above 12°C for the strain rate 10-2 s-1 accompanied the exothermic martensite transformation during loading and the temperature decrease related to the reverse endothermic transformation during unloading.

Keywords:

Powder metallurgy technology, shape memory alloys, DSC measurements, compression test, exothermic martensite transformation, endothermic reverse transformation

Affiliations:
Dutkiewicz J.M.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Maziarz W.-other affiliation
Czeppe T.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Lityńska L.-other affiliation
Nowacki W.K.-IPPT PAN
Gadaj S.P.-other affiliation
Luckner J.-IPPT PAN
Pieczyska E.A.-IPPT PAN
3.Pieczyska E.A., Tobushi H., Nowacki W.K., Gadaj S.P., Sakuragi T., Subloop deformation behavior of TiNi shape memory alloy subjected to stress-controlled loadings, MATERIALS TRANSACTIONS, ISSN: 1345-9678, Vol.48, No.10, pp.2679-2686, 2007
Abstract:

The main characteristics which appear in shape memory alloys (SMAs) are the shape memory effect and superelasticity. In applications of SMAs, the thermomechanical properties of SMAs are most important. The return-point memory does not appear under the stress-controlled conditions. Creep and stress relaxation can be induced due to the phase transformation in the subloop loading under the stress-controlled conditions. In order to design the SMA elements properly, it is important to understand the influence of the thermomechanical loading conditions on the nucleation and progress of the phase transformation and the corresponding deformation behaviors. In the present paper, the conditions for the nucleation and progress of the phase transformation are investigated for SMAs subjected to the subloop loadings under the stress-controlled conditions. The uniaxial tension tests for the TiNi SMAs were carried out in the superelastic region under the various thermomechanical loading conditions. The thermomechanical conditions for the progress of the phase transformation are discussed in the subloop loading under the stresscontrolled conditions. Strain increases during unloading and decreases during reloading under the stress-controlled subloop loading. These pseudoviscoelastic behaviors are important for the precise control of SMA elements.

Keywords:

shape-memory alloy, titanium-nickel alloy, subloop, superelasticity, creep, stress relaxation, neutral loading

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Nowacki W.K.-IPPT PAN
Gadaj S.P.-other affiliation
Sakuragi T.-Aichi Institute of Technology (JP)
4.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Tobushi H., Phase-transformation fronts evolution for strain- and stress- controlled tension tests in TiNi Shape Memory Alloy, EXPERIMENTAL MECHANICS, ISSN: 0014-4851, Vol.46, pp.531-542, 2006
Abstract:

Nucleation and development of phase transformation fronts in TiNi shape memory alloy subjected to the stress- and strain-controlled tension tests were investigated. A thermovision camera was applied to register the distribution of infrared radiation emitted by the specimen and to find its temperature variations. During the loading, narrow bands of considerably higher temperature corresponding to the martensitic phase, starting from the central part of the specimen and developing towards the specimen grips, under both approaches, were registered. The inclined bands of heterogeneous temperature distribution were observed also during the unloading process of the SMA, while the reverse transformation accompanied by temperature decrease took place. Thermomechanical aspects of martensitic and reverse transformations for various strain rates were analyzed under both stress- and strain-controlled tests.

Keywords:

Shape memory alloy, Martensitic transformation, Phase transformation front, Temperature change, Stress-controlled test, Strain-controlled test, Infrared thermography

Affiliations:
Pieczyska E.A.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
5.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Tobushi H., Superelastic deformation behaviors based on phase transformation bands in TiNi shape memory alloy, MATERIALS TRANSACTIONS, ISSN: 1345-9678, Vol.47, No.3, pp.670-676, 2006
Abstract:

Properties and characteristics of superelastic deformation behavior based on Lu¨ders-Like phase transformation bands in TiNi shape memory alloy (SMA) are presented. Temperature distributions accompanying the stress-induced phase transformations in the SMA are found using the infrared technique and employed for the investigation into nucleation and further development of the bands of martensitic and reverse transformations. Based on the temperature and the relevant mechanical characteristics it is noticed that just after crossing a certain threshold stress, narrow bands of considerably higher temperature, about 8K, corresponding to the martensitic phase, appear starting from the central part of the specimen and developing towards the both specimen borders. A few such bands parallel to each other occur at higher stresses and move towards the specimen grips, as well as their next generation, developing in almost perpendicular direction. The heterogeneous field of the temperature distribution was observed also during the unloading process, while the reverse transformation occurred, also inhomogeneous and related to the significant temperature decrease. Based on the tests carried out with various strain rates, an influence of the strain rate on the mechanical behavior was presented. Thermomechanical aspects of the martensitic and the reverse transformations were discussed.

Keywords:

superelastic deformation, shape memory alloy, phase transformation bands, temperature change, infrared camera

Affiliations:
Pieczyska E.A.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
6.Pieczyska E.A., Pęcherski R.B., Gadaj S.P., Nowacki W.K., Nowak Z., Matyjewski M., Experimental and theoretical investigations of glass fibre reinforced composite subjected to uniaxial compression for a wide spectrum of strain rates, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.58, pp.273-291, 2006
Abstract:

Results of static and dynamic compression tests for two types of glass fibrereinforced polypropylene composites are presented. Stress-strain curves showing the influence of the strain rate on the composite mechanical properties have been obtained.
A three-dimensional description of the material behavior during the deformation has been developed. The material constitutive parameters have been calculated.
Specification of the parameters and description of the methods used for their identification have been worked out. The results are discussed in terms of the deformation processes and the material non-homogeneity.

Keywords:

static and dynamic compression tests, glass fibrereinforced polypropylene composites, Stress-strain curves, constitutive model, three-dimensional description

Affiliations:
Pieczyska E.A.-IPPT PAN
Pęcherski R.B.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Nowak Z.-IPPT PAN
Matyjewski M.-other affiliation
7.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Tobushi H., Stress relaxation during superelastic behavior of TiNi shape memory alloy, INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS, ISSN: 1383-5416, Vol.23, pp.3-8, 2006
8.Pieczyska E.A., Tobushi H., Gadaj S.P., Nowacki W.K., Hoshito K., Makino Y., Martensite and reverse transformations in TiNi shape memory alloy by advance infrared technique, Journal of the Japanese Society for Experimental Mechanics, Vol.6, pp.175-180, 2006
9.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Hoshito K., Makino Y., Tobushi H., Characteristics of energy storage and dissipation in TiNi shape memory alloy, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, ISSN: 1468-6996, Vol.6, No.8, pp.889-894, 2005
Abstract:

The characteristics of energy storage and dissipation in TiNi shape memory alloys were investigated experimentally based on the superelastic properties under various thermomechanical loading conditions. The influence of strain rate, cyclic loading and temperature-controlled condition on the characteristics of energy storage and dissipation of the material was investigated. Temperature on the surface of the material was observed and the influence of variation in temperature on the characteristics was clarified. The results obtained can be summarized as follows. (1) In the case of low strain rate, the stress plateaus appear on the stress-strain curves due to the martensitic transformation and the reverse transformation during loading and unloading. In the case of high strain rate, the slopes of the stress–strain curves are steep in the phase-transformation regions during loading and unloading. The recoverable strain energy per unit volume increases in proportion to temperature, but the dissipated work per unit volume depends slightly on temperature. In the case of low strain rate, the recoverable strain energy and dissipated work do not depend on both strain rate and the temperature-controlled condition. (2) In the case of high strain rate, while the recoverable strain energy density decreases and dissipated work density increases in proportion to strain rate under the temperature-controlled condition, the recoverable strain energy density increases and dissipated work density decreases under the temperature-uncontrolled condition. In the case of the temperature-uncontrolled condition, temperature varies significantly due to the martensitic transformation and therefore the characteristics of energy storage and dissipation differ from these under the temperature-controlled condition. (3) In the case of cyclic loading, both the recoverable strain energy and dissipated work decrease in the early 20 cycles, but change slightly thereafter. (4) The influence of strain rate, cyclic loading and the environment on the characteristics of energy storage and dissipation is important to be considered in the design of shape memory alloy elements. q 2005 Elsevier Ltd. All rights reserved. Keywords: Shape memory ally; Superelasticity; Energy storage; Energy dissipation; Damping; Strain rate; Cyclic deformation; Titanium–nickel alloy; Environment

Keywords:

Shape memory ally, Superelasticity, Energy storage, Energy dissipation, Damping, Strain rate, Cyclic deformation, Titanium–nickel alloy, Environment

Affiliations:
Pieczyska E.A.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Hoshito K.-other affiliation
Makino Y.-other affiliation
Tobushi H.-Aichi Institute of Technology (JP)
10.Gadaj S.P., Nowacki W.K., Pieczyska E.A., Tobushi H., Temperature measurement as a new technique applied to the phase transformation study in a TiNi shape memory alloy subjected to tension, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.50, No.3, pp.661-674, 2005
11.Gadaj S.P., Nowacki W.K., Pieczyska E.A., Temperature changes of the polymer fibrous belts subjected to mechanical loading, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.53, No.2, pp.147-163, 2005
12.Gadaj S.P., Badania zmian energii zmagazynowanej w metalach w wyniku poddawania ich powierzchniowym zabiegom technologicznym (Praca doktorska), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.25, pp.1-97, 1991
13.Gadaj S.P., Oliferuk W., Pieczyska E., Emisja akustyczna podczas deformacji plastycznej stali węglowej, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.5, pp.1-15, 1988
14.Gadaj S.P., Kaczmarek J., Oliferuk W., Proces magazynowania energii podczas rozciągania metalu, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.28, pp.1-13, 1983
15.Gadaj S.P., Kaczmarek J., Oliferuk W., Pieczyska E., Wpływ obróbki powierzchniowej na proces magazynowania energii podczas rozciągania stali 1H18N9T, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.28, pp.1-9, 1983
16.Choroś J., Gadaj S.P., Kaczmarek J., Oliferuk W., Pieczyska E., Emisja akustyczna towarzysząca przemianom fazowym w deformowanej stali 1H18N9T, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.31, pp.1-16, 1982
17.Gadaj S.P., Gałkowska E., Kaczmarek J., Oliferuk W., Wyznaczanie energii zmagazynowanej w metalu podczas procesu rozciągania, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.36, pp.1-24, 1981
18.Gadaj S.P., Handzel-Powierza Z., Ziemba S., Żukowski S., Rola warstwy wierzchniej w procesach odkształceń i dekohezji, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.31, pp.1-33, 1976

List of chapters in recent monographs
1.
146
Nowacki W.K., Gadaj S.P., Pieczyska E.A., Tobushi H., Foundation of materials design, rozdział: Thermomechanical properties of TiNi shape memory alloy, Research Signpost (India), Kurzydłowski K.J., Major B., Zięba P. (Eds.), pp.195-240, 2006