Structure and properties of high-temperature alloys with the effect of shape memory in the system Cu−Al−Nb

Lelątko, J.; Morawiec, Natalia; Koval, Yu. N.; Kolomyttsev, V. I.

doi:10.1007/bf02474884

Cited by 11 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…al. 17 reported that for contents above 2.56% (wt.%) of niobium in the Cu-Al-Nb alloy the particle size in the high temperature phase decreases and the fine particles of primary phase segregate predominantly along the limits of grain. Besides that, they observed the degree of shape recovery of Cu-Al-Nb alloys decreases with increasing Nb content from 2.56% to 7.86% (wt.%).…”

Section: Resultsmentioning

confidence: 99%

Influence of Mechanical Cycling on Residual Strain in Superelastic Cu-Al-Be-Nb Alloys

et al. 2019

View full text Add to dashboard Cite

The understanding of the stabilization mechanism of martensite used to obtain alloys with high hysteresis and the possibility of recovering this martensite (residual strain) by heating at temperatures higher than A s and A f have been fundamental for application in bonding devices. One of the possibilities to enhance residual strain is through mechanical cycling. This work evaluated the influence of number of cycles and the effect of precipitation of Nb-rich particles as mechanisms to increase residual strain in superelastic Cu-Al-Be-Nb alloys. The results showed that the presence of Nb-rich precipitates was not a predominant factor for the enhancement of residual strain. In addition, mechanical cycling has proved to be an efficient mechanism for raising residual strain, and consequently increasing the amount of martensite retained. However, the gain of residual strain is accompanied by an increase of plastic deformation.

show abstract

Section: Resultsmentioning

confidence: 99%

Influence of Mechanical Cycling on Residual Strain in Superelastic Cu-Al-Be-Nb Alloys

et al. 2019

View full text Add to dashboard Cite

show abstract

“…This is an apparent indication that the alloy thermodynamic states are not influenced by either the direction of transformation or the number of thermal cycles, as also reported by Pereira et al 6 . Then, a better stability of transformation energies was verified for the modified alloys A and B and a gradual reduction for alloy C due to the thermal degradation associated with the diffusion processes at relatively high temperatures of cycled heating 9 . For all the modified alloys, it was found that these energies agree with the transformation enthalpies reported in the literature for Cu-Al-Ni SMA with 13.5 to 14.0 %wt.…”

Section: Verification Of Phase Transformation By Differential Scanninmentioning

confidence: 93%

“…This behavior was also observed for the Cu-Al-Nb SMA, where after the fifth thermal cycle, at temperatures higher than 250°C, the phase transformation tends to disappear completely. The low thermal stability observed in the alloys of the Cu-Al-Nb system is due to intense development of the diffusion processes at relatively high temperatures of the cycled heating 9 . This is probably the case for our modified alloy C (CMT).…”

Section: Verification Of Phase Transformation By Differential Scanninmentioning

confidence: 99%

Analysis of Compositional Modification of Commercial Aluminum Bronzes to Obtain Functional Shape Memory Properties

2017

View full text Add to dashboard Cite

In copper-based shape memory alloys (SMAs), some exceptional phenomena, such as the shape memory effect (SME) or superelasticity (SE), are observable. However, commercial aluminum bronzes, Cu 3 Al-based alloys, do not present these functional properties (SME and/or SE) in their original state. Thus, since one of the main copper-based SMA systems is the Cu-Al-Ni alloy, this paper aims to analyze the modification of these commercial aluminum bronzes to SMA by the addition small amounts of Cu, Al and/or Ni. These modified bronzes were reprocessed by induction melting and injected by centrifugation into a ceramic coating mold. The modifications were made to determine the nominal composition for a Cu-13,0Al-4,0Ni (%wt) SMA. The effectiveness of the modifications was verified by differential scanning calorimetry (DSC) thermal analysis. All modified Cu-Al-Ni bronzes presented DSC peaks of the thermoelastic martensitic phase transformation, showing that SMA behavior was achieved, while the non-modified bronzes revealed no transformation. These results were supported by Vickers hardness (HV), X-ray diffraction (XRD), semi quantitative composition by EDS analysis and optical microscopy.

show abstract

“…Tables I and II are constructed from a detailed data pool gleaned from the literature. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Tables I and II give the inputs and outputs of the GP. The inputs are the elements to produce the alloy and the thermal treatments that are applied to the alloy.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Thermodynamic Equilibrium Temperature of Cu-Based Shape-Memory Smart Materials

Eskil

Aldaş

Özkul

2014

Metall Mater Trans A

View full text Add to dashboard Cite

The thermodynamic equilibrium temperature (T 0 ) is an important factor in the austenite and martensitic phases. In this study, the effects of alloying elements and heat treatments on T 0 temperature were investigated using Genetic Programming (GP) which has become one of the tools used in the study of condensed matter. Due to the changes in T 0 , it is possible to analyze the changes in the entropy of the phase transitions. The data patterns of the GP formulation are based on well-established experimental results from the literature. The results of the GP-based formulation were compared with experimental results and found to be reliable with a very high correlation (R 2 = 0.965 for training and R 2 = 0.952 for testing).

show abstract

Structure and properties of high-temperature alloys with the effect of shape memory in the system Cu−Al−Nb

Cited by 11 publications

References 0 publications

Influence of Mechanical Cycling on Residual Strain in Superelastic Cu-Al-Be-Nb Alloys

Influence of Mechanical Cycling on Residual Strain in Superelastic Cu-Al-Be-Nb Alloys

Analysis of Compositional Modification of Commercial Aluminum Bronzes to Obtain Functional Shape Memory Properties

Prediction of Thermodynamic Equilibrium Temperature of Cu-Based Shape-Memory Smart Materials

Contact Info

Product

Resources

About