Ageing effects in a Cu-Al-Ni shape memory alloy

Daricek, T.; Lašek, J.; Zárubová, N.; Novák, V.; Bartuška, P.

doi:10.1051/jp4:2001831

Cited by 9 publications

(4 citation statements)

References 16 publications

(37 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The transition curves of the forward and reverse transitions for the Cu-Al-Ni-xTi (x = 0.4, 0.7 and 1.0 mass%) aged at different times and temperatures are illustrated in It was found that with an increase in aging time and temperature, the transition temperatures shift toward high temperatures, which is in agreement with other researchers [20][21][22][23][24]. This shifting is mainly attributed to the type and morphology of the martensitic phase, as well as the presence of the precipitates [25,26].…”

Section: Dsc Analysissupporting

confidence: 87%

X-phase precipitation in aging of Cu–Al–Ni–xTi shape memory alloys and its influence on phase transition behavior

Saud

Hamzah

Abubakar

et al. 2015

J Therm Anal Calorim

View full text Add to dashboard Cite

The present work aims to investigate the aging treatment effects on the microstructure, transition characteristics, and mechanical properties of Cu-Al-Ni-xTi shape memory alloys. The aging treatment of the homogenized and modified alloys of Cu-Al-Ni-xTi results in variations of the martensite morphology, volume fraction, and precipitate size. These variations in the features of precipitates have an obvious effect on transition behavior and mechanical properties. The transition temperatures are increased slightly with an increase in the aging time and temperatures; such increase is mainly attributed to changes in the c 0 1 and b 0 1 morphology and distribution, along with the precipitates. The thermodynamic parameters (DH and DS) tend to decrease with an increase in the aging time and temperatures. Moreover, the brittleness, low strength, and poor processability of Cu-Al-Ni alloys greatly limit their application. We attempted to improve the mechanical properties without losing the thermoelastic properties through the additions of Ti and appropriate aging treatments. The highest tensile strength and strain of 640 MPa and 4.3 % were obtained in alloy of Cu-Al-Ni-0.7 mass% Ti aged at 250°C for 24 h and 100°C for 48 h, respectively. The shape memory behavior of the alloys was studied using a specially designed machine. The strain recovery by shape memory effect of the alloys increases with an increase in the aging tomes and temperature, where the highest recovery (100 %) is obtained with the alloy of Cu-Al-Ni-0.7 mass% Ti after being aged at 250°C for 24 h.

show abstract

Section: Dsc Analysissupporting

confidence: 87%

X-phase precipitation in aging of Cu–Al–Ni–xTi shape memory alloys and its influence on phase transition behavior

Saud

Hamzah

Abubakar

et al. 2015

J Therm Anal Calorim

View full text Add to dashboard Cite

show abstract

“…To enhance ductility, additional elements can be alloyed to the base alloys such as Mn, Fe, or Ti. The processes behind the ageing phenomena are well described in the Cu-Al based SMAs [1][2][3][4][5][6][7]. These processes include the ordering transitions of the parent β phase and the formation of the equilibrium γ2 and α phases.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Kinetic of a Bainitic Reaction upon Heating in a CuAlNiMn and a CuAlNiMnFe Shape Memory Alloy

Benke

Mertinger

Barkóczy

2013

MSF

View full text Add to dashboard Cite

The examination of solid state processes leading to the degradation of the shape memory behaviour is essential with respect to the suitability of shape memory alloys. Besides degradation processes occurring during relatively long periods of time called ageing, bainitic reactions that suddenly degrade the shape memory behaviour were also observed in many Cu-based shape memory alloys. The mechanisms and effects of the bainitic reactions on the shape memory characteristics were investigated in many Cu-based systems, but the kinetic of the reaction was not examined so far. In the present paper, an examination was carried out on a CuAlNiMn and a CuAlNiMnFe shape memory alloy to reveal what kinetic model describes the bainitic reaction occurring and thus completely destroying the shape memory effect during one stage of heating.

show abstract

“…Because transformation temperatures are very sensitive on the concentration change, transformation temperatures shift due to the precipitation processes. In addition, if the composition of the matrix is strongly modified, the ability of thermoelastic transformation is destroyed [1,5,6,7,8]. Today's most widely shape memory alloys are NiTi alloys.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Ageing Phenomena in CuAlNi Based Shape Memory Alloys

Benke

Mertinger

Nagy

et al. 2007

MSF

View full text Add to dashboard Cite

The ageing phenomena and its effect on the thermoelastic martensitic transformation was investigated in three Cu-base SMAs. The transformation temperatures shifted to higher temperatures due to aging in the beta-phase. To increase the alloy’s ductility, a definite amount of Mn (4 wt%) and Fe (2 wt%) were added to the ternary alloy. The thermoelastic martensitic transformation was found in the not-aged samples of the CuAlNiMn and CuAlNiMnFe alloys. This transformation was destroyed due to ageing heat treatments by a fairly unknown exothermic process. The thermoelastic martensitic transformation appeared again in the aged CuAlNiMn and CuAlNiMnFe samples after keeping them on room temperature for a few months. This phenomena was investigated by DSC, SEM, TEM, and XRD.

show abstract

Ageing effects in a Cu-Al-Ni shape memory alloy

Cited by 9 publications

References 16 publications

X-phase precipitation in aging of Cu–Al–Ni–xTi shape memory alloys and its influence on phase transition behavior

X-phase precipitation in aging of Cu–Al–Ni–xTi shape memory alloys and its influence on phase transition behavior

Investigation of the Kinetic of a Bainitic Reaction upon Heating in a CuAlNiMn and a CuAlNiMnFe Shape Memory Alloy

Investigation of Ageing Phenomena in CuAlNi Based Shape Memory Alloys

Contact Info

Product

Resources

About