Effect of ageing on the reverse martensitic phase transformation behaviors of a CuAlMn shape memory alloy

Wang, Qingzhou; Han, Fuzhu; Cui, Chunxiang; Bu, Shaojing; Bai, Ling

doi:10.1016/j.matlet.2007.04.025

Cited by 29 publications

(10 citation statements)

References 14 publications

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“…During heating process, the decrease in the reverse MT temperatures can be attributed to the decrease in the content of quenched‐in vacancies. There are large quantities of quenched‐in vacancies in the quenched Cu‐based SMAs, and these vacancies can impose a pinning effect on the martensite interfaces and lead to a remarkable increase in the reverse MT temperatures . Fortunately, these quenched‐in vacancies could be gradually annihilated during subsequent aging treatments .…”

Section: Resultsmentioning

confidence: 99%

Effects of Parent Phase Aging and Nb Element on the Microstructure, Martensitic Transformation, and Damping Behaviors of a Cu–Al–Mn Shape Memory Alloy

Wang

Yin

et al. 2020

Physica Status Solidi (a)

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It is recognized that both parent phase aging and element addition can dramatically enhance the comprehensive properties of Cu‐based shape memory alloys (SMAs). However, further in‐depth studies are still needed to clarify the detailed laws and mechanisms. Herein, the effects of parent phase aging and Nb element on the microstructure, martensitic transformation (MT), and damping behaviors of a Cu–Al–Mn SMA are systematically studied. It is found that both the damping at low temperatures and the height of internal friction peak arising from the reverse MT of the Cu–Al–Mn SMA can be improved by the parent phase aging due to the increase in interfacial mobility. When the aging temperature reaches 600 °C, the best damping can be obtained. Nb forms AlNb3 phase in the Cu–Al–Mn matrix. Due to the pinning effect of the AlNb3 phase on grain boundaries, the grains of the Cu–Al–Mn SMA can be remarkably refined. With the increase in Nb content, the damping of the 600 °C aged Cu–Al–Mn SMA increases first and then decreases. The associated mechanisms are discussed. This work aims to provide theoretical basis and technical support for the improvement of damping property of Cu‐based SMAs.

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Section: Resultsmentioning

confidence: 99%

Effects of Parent Phase Aging and Nb Element on the Microstructure, Martensitic Transformation, and Damping Behaviors of a Cu–Al–Mn Shape Memory Alloy

Wang

Yin

et al. 2020

Physica Status Solidi (a)

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“…Key to maximize these effects belong to the stabilization of the intermetallic high temperature β-phase and its low temperature successors transformation window near the intended application temperature 1,2 . The austenitic β-phase arranged to the lower order system β 1 (L21; Cu2AlMn) and martensitic phase stabilization of (unstable) β´3 (18R) to (stable) γ´3 (2H) ratio can be adjusted by quenching and the amount of aluminium (Al) and manganese (Mn) 3,4,5 . In 6,7 heat treatments above 1073 K and quenching are considered to improve the damping capacity.…”

Section: Introductionmentioning

confidence: 99%

Impact of Alloy Composition and Thermal Stabilization on Martensitic Phase Transformation Structures in CuAlMn Shape Memory Alloys

et al. 2018

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Alloys of CuAlMn are known as cheap, high strength shape memory alloys with an excellent damping capacity within their austenitic-martensitic phase transformation, compared to alloy systems like NiTi, CuZnAl or MnCu. But CuAlMn alloys have disadvantage due to generation of voids by a high shrinkage which further increases the existing proneness to stress cracks during rapid cooling. Alloying grain refining elements improves the stress crack resistance and enables a wide range of rapid quenching parameters which are needed to control the temperature of martensitic phase transformation. Additionally, the elements itself influence the in-or decreasing of the phase transformation temperature and the SMA effects. Furthermore, some of these elements can reduce the internal friction indirectly by decomposing areas of metastable martensite into its stabilized forms, where no transformation occurs. This thermic stability can be calculated by the concentration of valence electrons in a unit cell. The proneness to ageing is controlled by multistep heat treatments. Annealing and rapid quenching into the area of martensitic phase transformation maximize the generation of point defects. A high amount of point defects contradicts the negative effect of pinning. It also preserves the material from extreme brittleness. The influences of these effects are shown at single cantilever bending beams by elastic strain amplitude (ε = 12E-4) depending measurements of internal friction at natural frequency along the ageing at room temperature (293 K) up to 2500 h. The samples are annealed at 1123 K for 15 min (CuAl14Mn2) and 1100K for 30min (CuAl11Mn5) afterwards rapid quenched to 370 K with no further thermic stabilisation. The base alloy of CuAl14.1Mn2.0Ni1.9Fe0.4 had an internal friction measured as logarithmic Decrement (δ) of 0.155 and 0.11 after 2500 h of ageing at RT. The phase transformation is located between 284 K and 352 K, measured by DSC. The alloy of CuAl11.1Mn5.5Zn2.9Ni2.1 had a logarithmic decrement of 0.31 and diminish continuously to 0.12 after 2500 h of ageing at RT. The phase transformation is located between 287 K and 318 K.

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“…Among the Cu based shape memory alloys mostly investigated, the Cu-Al-Ni [1][2][3][4][5][6][7], Cu-Al-Zn [8][9][10][11][12] and Cu-Al-Mn [13][14][15][16][17][18][19][20][21] alloys have been studied extensively. But most Cu-Al-Ni and Cu-Zn-Al polycrystalline shape memory alloys are brittle and cannot therefore be cold worked.…”

Section: Introductionmentioning

confidence: 99%

“…Attempts to improve the ductility of these polycrystalline Cu based shape memory alloys by grain refinement have only resulted in limited success. However, it has been reported in recent studies that Cu-Al-Mn alloys with low aluminum contents show excellent ductility because their parent phase with L2 structure possesses comparatively a lower degree of order [21,22]. This feature could well be useful for the shape memory alloys to exhibit better pseudoelasticity.…”

Section: Introductionmentioning

confidence: 99%

Changes in the properties of Cu-Al-Mn shape memory alloy due to quaternary addition of different elements

et al. 2015

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Advantages of Cu based shape memory alloy include amongst other features, high transformation temperature, low cost of production, ease in manufacturing processes and ability to vary the achieved properties through alloying additions. It has been often reported that these alloys are very sensitive to the alloying additions in terms of properties achieved and phase precipitation necessary for development of shape memory properties. This behaviour in Cu based shape memory alloys i.e. being very sensitive to its constituents can be used positively to design alloys with pre set properties if the alloying additions and their percentages are properly controlled.In an attempt to understand the effect of different alloying additions, 2% of different elements [Zn, Si, Mg & Cr] were added to a known Cu-based shape memory alloy [Cu-12.5 wt% of Al-5 wt % of Mn]. The objective was to ascertain changes or improvements achieved due to the additions in terms of microstructural changes, hardness, phase precipitation and transformation temperatures. Attempts have been made to analyze the changes in properties achieved in the base Cu-Al-Mn alloys due to the quaternary additions. Grain structure with α+β phases, which is a pre requisite for martensite formation on quenching is seen in all the alloys indicating that all the alloys have potential to exhibit the shape memory behaviour. The martensite formation with different morphologies is observed in the quenched samples however. XRD results have identified the precipitated phases to be the martensitic phases. The DSC results indicate clear transformation peaks in most of the samples with significantly high transformation temperatures. The findings confirm the variation in properties achieved due to different additions and improvements achieved in terms of higher transformation temperatures and martensite formation due to the alloying additions. An attempt has been made to understand the findings.

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Effect of ageing on the reverse martensitic phase transformation behaviors of a CuAlMn shape memory alloy

Cited by 29 publications

References 14 publications

Effects of Parent Phase Aging and Nb Element on the Microstructure, Martensitic Transformation, and Damping Behaviors of a Cu–Al–Mn Shape Memory Alloy

Effects of Parent Phase Aging and Nb Element on the Microstructure, Martensitic Transformation, and Damping Behaviors of a Cu–Al–Mn Shape Memory Alloy

Impact of Alloy Composition and Thermal Stabilization on Martensitic Phase Transformation Structures in CuAlMn Shape Memory Alloys

Changes in the properties of Cu-Al-Mn shape memory alloy due to quaternary addition of different elements

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