Thermal fatigue damage of Cu–Cr–Zr alloys

• Published in: Journal of nuclear materials Vol. 443; no. 1-3; pp. 8 - 16
• Main Authors: Chatterjee, Arya, Mitra, R., Chakraborty, A.K., Rotti, C., Ray, K.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2013; Elsevier
• Subjects: AGING MECHANISMS; Alloys; Applied sciences; CHROMIUM COPPERS; Coalescence; Controled nuclear fusion plants; COPPER ALLOYS (40 TO 99.3 CU); Copper base alloys; Damage; ELECTRICAL CONDUCTIVITY; Energy; Energy. Thermal use of fuels; Exact sciences and technology; FATIGUE PROPERTIES; Fission nuclear power plants; Fuels; HARDNESS; Installations for energy generation and conversion: thermal and electrical energy; Lattice strain; Nuclear fuels; PROPERTIES; RESIDUAL STRESS; Resistivity; STRAIN; Tensile properties; Thermal fatigue; Tokamak; Electrical conductivity; Ageing; Zirconium alloy; Heat flow; Thermal fatigue; Tensile property; Stress strain; Standards; Nuclear reactor; Nuclear fusion reactor; Coalescence; Microstructure; Residual stress; Damaging
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2013.06.046

•This is a pioneering study of thermal fatigue damage (TFD) in aged Cu–Cr–Zr alloys.•Among various parameters, conductivity and elastic modulus sensitively reveal TFD.•Finer precipitates cause higher TFD in this alloy when aged at 480°C than at 500°C.•Mechanism of TFD for Cu–Cr–Zr alloys used for ITER has been described. The primary aim of this investigation is to examine thermal fatigue damage (TFD) in Cu–Cr–Zr alloys used in High Heat Flux components of Tokamak and its subsystems. Thermal fatigue experiments have been carried out between 290°C and 30°C, which is analogous to the condition of service application on two Cu–Cr–Zr alloys having different aging treatments. The extents of TFD have been examined by standard measurements of electrical conductivity, lattice strain, residual stress and dynamic elastic modulus, supplemented by characterizations of microstructure and determination of hardness and tensile properties. The results lead to infer that the relative amounts of damage are different in the two alloys which are further dependent on their aging conditions; the reasons for the observed difference have been explained. The operative mechanisms of TFD are revealed to be as formation and subsequent coalescence of microvoids, and/or initiation and growth of microcracks.