Influences of 2.5wt% Mn addition on the microstructure and mechanical properties of Cu-Al-Ni shape memory alloys

Sarı, Uğur

doi:10.1007/s12613-010-0212-0

Cited by 59 publications

(19 citation statements)

References 21 publications

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“…Although in the microstructure of CuAlNiTa alloy, which has been heat treated at 1273 K, shows martensite phases, there is no sign of phase transformation in its DSC measurement. In figure 8 grain boundaries cannot be seen on the given scale, while Sari [33] found that as-cast CuAlNi and CuAlNiMn alloys have shown microscopic grain about 1400 and 350 μm, respectively. The production technique is an important parameter that affects the grain size and hence all mechanical properties.…”

Section: Crystal and Microstructural Analysismentioning

confidence: 95%

“…Since the SEM images, has been taken in room temperature, they show g ¢ 1 and b ¢ 1 phases in the matrix of all specimens, so the results support the DSC measurements which illustrate that the samples have martensite phase at room temperature. It is proved that g ¢ 1 (2 H) has higher Al content compared to b ¢ 1 (18 R) phase [33]. In addition, the amount of these types of martensite phases can influence transformation characteristics such as PTTs [34,35].…”

Section: Crystal and Microstructural Analysismentioning

confidence: 99%

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Thermal stability and some thermodynamics analysis of heat treated quaternary CuAlNiTa shape memory alloy

Kök

Qader

Mohammed

et al. 2019

Mater. Res. Express

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This study presents the heat treatment effect on a quaternary Cu 79 Al 13 Ni 4 Ta 4 (wt%) shape memory alloy. The induction technique was used for melting the alloy and then four pieces of the alloy were heat-treated at (673 K, 873 K, 1073 K, and 1273 K) for one hour. Some physical parameters were characterized using DSC, XRD, and SEM-EDX. The as-cast and heat-treated samples were studied in terms of phase transformation temperatures, enthalpy change, entropy change, Gibbs free energy, and elastic energy. The transformation temperature was increased by applying heat treatment. Martensitic phase transformation at heat treatment temperature of 1273 K was not observed. Besides, after rising heat treatment temperature, some new phases such as ¡ b ¢ ¢ and 1 1 were specified in XRD patterns and SEM images. Generally, for heat-treated samples, the transformation temperature remains almost constant after the 3rd cycle. However, the thermal stability of the as-cast alloy was not affected through thermal cycling.

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Section: Crystal and Microstructural Analysismentioning

confidence: 95%

Section: Crystal and Microstructural Analysismentioning

confidence: 99%

Thermal stability and some thermodynamics analysis of heat treated quaternary CuAlNiTa shape memory alloy

Kök

Qader

Mohammed

et al. 2019

Mater. Res. Express

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“…The quenched samples were ground and polished and then etched in a solution containing 2.5 g ferric chloride acid (FeCl 3 AE6-H 2 O) and 48 mL methanol (CH 3 OH) in 10 mL HCl for 4 minutes. [23][24][25] C. Mechanical Tests…”

Section: B Materials Characterizationmentioning

confidence: 99%

Effect of Quarterly Element Addition of Cobalt on Phase Transformation Characteristics of Cu-Al-Ni Shape Memory Alloys

Saud

Bakar

Hamzah

et al. 2015

Metall Mater Trans A

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In the current study, a new type of Cu-based shape memory alloys with the function of shape memory effect was successfully produced with the introduction of high-purity Co precipitates between the phases of Cu-Al-Ni shape memory alloy. The microstructure, transformation characteristics, and mechanical properties were systematically investigated by means of differential scanning calorimetry, field emission scanning electron microscopy, energy dispersive spectroscopy (EDS), transmission electron microscopy, X-ray diffraction (XRD), a tensile test, a hardness test, and a shape memory effect test. The typical microstructures show that a new phase was formed, known as the c 2 phase, and the volume friction and the size of this phase were gradually increased with the increasing Co content. According to the results of the XRD and EDS, it was confirmed that the c 2 phase represents a compound of Al 75 Co 22 Ni 3 . However, the presence of c 2 phase in the modified alloys was found to result in an increase of the transformation temperatures in comparison with the unmodified alloy. Nevertheless, it was found that with 1 wt pct of Co addition, a maximum ductility of 7 pct was achieved, corresponding to an increase in the strain recovery by the shape memory effect to 95 pct with respect to the unmodified alloy of 50 pct.

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“…Their very high elastic anisotropy and large grain sizes cause brittle and poor mechanical properties owing to the high degree of order in the parent phase with B2, DO 3 or L2 1 structure. Adding some alloying elements such as Mn, Ti, Fe, Zr, and B to the alloys can significantly improve their ductility and properly modify their operating temperatures [4][5][6][7][8][9]. Particularly, Mn addition in the alloys has been proved to enhance the thermoelastic and pseudoelastic behaviors [6].…”

Section: Introductionmentioning

confidence: 99%

“…These ordered structures also transform into close-packet martensite structures (6R, 18R, and 2H; R rhombohedral and H hexagonal) with further cooling [10][11]. On the other hand, the characteristics of martensitic transformations are very sensitive to the order degree of β phase and the precipitate process of the stable phase due to the metastable character of this phase [9,[12][13]. In addition, the precipitation and the aging phenomena become dominant in the alloys when they are used at high temperature.…”

Section: Introductionmentioning

confidence: 99%

Effects of aging on the microstructure of a Cu-Al-Ni-Mn shape memory alloy

Sarı

Kırındı

Özcan

et al. 2011

Int J Miner Metall Mater

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The influence of aging on the microstructure and mechanical properties of Cu-11.6wt%Al-3.9wt%Ni-2.5wt%Mn shape memory alloy (SMA) was studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometer, and differential scanning calorimeter (DSC). Experimental results show that bainite, γ 2 , and α phase precipitates occur with the aging effect in the alloy. After aging at 300°C, the bainitic precipitates appear at the early stages of aging, while the precipitates of γ 2 phase are observed for a longer aging time. When the aging temperature increases, the bainite gradually evolves into γ 2 phase and equilibrium α phase (bcc) precipitates from the remaining parent phase. Thus, the bainite, γ 2 , and α phases appear, while the martensite phase disappears progressively in the alloy. The bainitic precipitates decrease the reverse transformation temperature while the γ 2 phase precipitates increase these temperatures with a decrease of solute content in the retained parent phase. On the other hand, these precipitations cause an increasing in hardness of the alloy.

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Influences of 2.5wt% Mn addition on the microstructure and mechanical properties of Cu-Al-Ni shape memory alloys

Cited by 59 publications

References 21 publications

Thermal stability and some thermodynamics analysis of heat treated quaternary CuAlNiTa shape memory alloy

Thermal stability and some thermodynamics analysis of heat treated quaternary CuAlNiTa shape memory alloy

Effect of Quarterly Element Addition of Cobalt on Phase Transformation Characteristics of Cu-Al-Ni Shape Memory Alloys

Effects of aging on the microstructure of a Cu-Al-Ni-Mn shape memory alloy

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