The main scope of this work is to describe the microstructure evolution of single-crystal (SX) superalloy René N4 during creep and static aging at high temperatures, in function of time, stress and temperature. During creep at high temperatures, SX microstructure evolves from a dense and ordered distribution of cuboidal γ′ particles to a configuration characterized by alternate rafts of γ′ phase and γ matrix, through a process known as rafting. The microstructural evolution of superalloys is very important to derive models able to predict service conditions of a component through microstructural analysis. In this work two microstructural parameters were identified and analyzed for René N4: matrix channels width w along the [0 0 1] lattice direction and periodicity width λ, given by the sum of w and the width of the γ′ precipitates along [0 0 1]. Both parameters were measured on some creep-damaged and some statically aged specimens, as well as on the virgin material to analyze their trends in function of time, temperature and stress. In particular, the parameter Δλ looks independent of both the stress level and the microstructural morphology and could be used in future works to develop microstructural evolution model of René N4 in function of service time and temperature.
Giorgetti, A., Monti, C., Tognarelli, L., Mastromatteo, F. (2017). Microstructural evolution of René N4 during high temperature creep and aging. RESULTS IN PHYSICS, 7, 1608-1615 [10.1016/j.rinp.2017.04.027].
Microstructural evolution of René N4 during high temperature creep and aging
Giorgetti A.
;
2017-01-01
Abstract
The main scope of this work is to describe the microstructure evolution of single-crystal (SX) superalloy René N4 during creep and static aging at high temperatures, in function of time, stress and temperature. During creep at high temperatures, SX microstructure evolves from a dense and ordered distribution of cuboidal γ′ particles to a configuration characterized by alternate rafts of γ′ phase and γ matrix, through a process known as rafting. The microstructural evolution of superalloys is very important to derive models able to predict service conditions of a component through microstructural analysis. In this work two microstructural parameters were identified and analyzed for René N4: matrix channels width w along the [0 0 1] lattice direction and periodicity width λ, given by the sum of w and the width of the γ′ precipitates along [0 0 1]. Both parameters were measured on some creep-damaged and some statically aged specimens, as well as on the virgin material to analyze their trends in function of time, temperature and stress. In particular, the parameter Δλ looks independent of both the stress level and the microstructural morphology and could be used in future works to develop microstructural evolution model of René N4 in function of service time and temperature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
