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Lee, K. L.; Whitehouse, A.F.; Russell, Alan M.; Wongpreedee, Kageeporn; Hong, Sung Il; Withers, Philip J.

doi:10.1023/a:1025196700785

Cited by 7 publications

(10 citation statements)

References 10 publications

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“…This shows that under a similar testing condition (same temperature), more voids are allowed to nucleate and grow, without immediately leading to failure, The more uniform distribution of damage at high temperatures can be linked to increasing tolerance to damage due to a fairly good toughness of the Cu-Cr composites. It was also suggested by the present authors [4] that the higher strain-rate sensitivity at higher temperatures promotes more uniform distribution of damage and high ductility. It should be noted in Figure 13(a) that voids as large as 30 m did not lead to final fracture.…”

Section: Damage Evolution and Fracturesupporting

confidence: 78%

“…The similarity of the activation energy and the stress exponent of the Cu-Cr composites of the present study to those of pure Cu suggest that the contribution of deformation of Cr fibers to the creep deformation is negligible. The present authors [4] observed that the contribution of Cr fibers to the strength of Cu-Cr composites is greater at high temperatures (300°C to 600°C). This suggests that the elongation of Cr fibers is not significant for high-temperature creep, which is compatible with the observation of the similarity of creep activation energy and the stress exponent in Cu-Cr composites and pure Cu.…”

Section: B Creep Deformationsupporting

confidence: 50%

“…In the present study, Cr fibers act as athermal obstacles and increase the athermal strengthening component, which would increase the creep resistance greatly. [4] Since the creep deformation proceeds by overcoming thermal obstacles in the Cu matrix, the stress exponent and the activation energy are not appreciably modified by the presence of relatively big Cr fibers. The similarity of the activation energy and the stress exponent of the Cu-Cr composites of the present study to those of pure Cu suggest that the contribution of deformation of Cr fibers to the creep deformation is negligible.…”

Section: B Creep Deformationmentioning

confidence: 99%

“…[4,34] Comparing the extent of damage observed under creep and tensile deformation shows that the creep specimens exhibit a higher level of damage than material subjected to tensile testing. This shows that under a similar testing condition (same temperature), more voids are allowed to nucleate and grow, without immediately leading to failure, The more uniform distribution of damage at high temperatures can be linked to increasing tolerance to damage due to a fairly good toughness of the Cu-Cr composites.…”

Section: Damage Evolution and Fracturementioning

confidence: 99%

“…Among the several Cu-X composites, Cu-Cr composites have been studied by several research groups and were found to possess a desirable combination of attributes. [1][2][3][4][5][6][7][8][9][10][11][12][13] Compared to other Cu-X composites, Cu-Cr composites offer lower cost (the cost of Cr is roughly one-tenth that of Nb), lower solubility of the X element in the Cu matrix, and a higher elastic modulus; these attributes make Cu-Cr composites a promising material for many potential applications, particularly at elevated temperatures such as aerospace propulsion systems and fusion power plants.…”

Section: Introductionmentioning

confidence: 99%

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Creep behavior of copper-chromium in-situ composite

Lee

Whitehouse

Hong

et al. 2004

Metall Mater Trans A

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Creep deformation and fracture behaviors were investigated on a deformation-processed Cu-Cr in-situ composite over a temperature range of 200 °C to 650 °C. It was found that the creep resistance increases significantly with the introduction of Cr fibers into Cu. The stress exponent and the activation energy for creep of the composite at high temperatures (≥400 °C) were observed to be 5.5 and 180 to 216 kJ/mol, respectively. The observation that the stress exponent and the activation energy for creep of the composite at high temperatures (≥400 °C) are close to those of pure Cu suggests that the creep deformation of the composite is dominated by the deformation of the Cu matrix. The high stress exponent at low temperatures (200 °C and 300 °C) is thought be associated with the as-swaged microstructure, which contains elongated dislocation cells and subgrains that are stable and act as strong athermal obstacles at low temperatures. The mechanism of damage was found to be similar for all the creep tests performed, but the distribution and extent of damage were found to be very sensitive to the test temperature. Creep deformation and fracture behaviors were investigated on a deformation-processed Cu-Cr in-situ composite over a temperature range of 200°C to 650°C. It was found that the creep resistance increases significantly with the introduction of Cr fibers into Cu. The stress exponent and the activation energy for creep of the composite at high temperatures (Ն400°C) were observed to be 5.5 and 180 to 216 kJ/mol, respectively. The observation that the stress exponent and the activation energy for creep of the composite at high temperatures (Ն400°C) are close to those of pure Cu suggests that the creep deformation of the composite is dominated by the deformation of the Cu matrix. The high stress exponent at low temperatures (200°C and 300°C) is thought be associated with the as-swaged microstructure, which contains elongated dislocation cells and subgrains that are stable and act as strong athermal obstacles at low temperatures. The mechanism of damage was found to be similar for all the creep tests performed, but the distribution and extent of damage were found to be very sensitive to the test temperature. Disciplines Materials Science and Engineering | Metallurgy

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Section: Damage Evolution and Fracturesupporting

confidence: 78%

Section: B Creep Deformationsupporting

confidence: 50%

Section: B Creep Deformationmentioning

confidence: 99%

Section: Damage Evolution and Fracturementioning

confidence: 99%