Reordering kinetics of ion-disordered Ni Al

Ewert, J. C.; Schmitz, Guido

doi:10.1007/s100510070118

Cited by 14 publications

(6 citation statements)

References 1 publication

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Order By: Relevance

“…Consistent with previous reports [19], at temperatures hotter than T c = 740 K, order parameter of at least 0.3 is preserved at all irradiation doses tested. Beyond this critical temperature, the mono-vacancies are mobile and promote order.…”

supporting

confidence: 92%

Effect of He on the Order-Disorder Transition in Ni3Al under Irradiation

et al. 2020

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The order-disorder transition in Ni-Al alloys under irradiation represents an interplay between various re-ordering processes and disordering due to thermal spikes generated by incident high energy particles. Typically, ordering in enabled by diffusion of thermally-generated vacancies, and can only take place at temperatures where they are mobile and in sufficiently high concentration. Here, in-situ transmission electron micrographs reveal that the presence of He-usually considered to be a deleterious immiscible atom in this material-promotes reordering in Ni3Al at temperatures where vacancies are not effective ordering agents. A rate-theory model is presented, that quantitatively explains this behavior, based on parameters extracted from atomistic simulations. These calculations show that the V2He complex is an effective agent through its high stability and mobility. It is surmised that immiscible atoms may stabilize reordering agents in other materials undergoing driven processes, and preserve ordered phases at temperature where the driven processes would otherwise lead to disorder.

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supporting

confidence: 92%

Effect of He on the Order-Disorder Transition in Ni3Al under Irradiation

et al. 2020

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“…The origin of the above phenomenon, as well as a general atomistic mechanism of "order-order" relaxations in systems with particular types of superstructure has been a subject of studies carried out for several years by means of computer simulations [5][6][7][8][9][10]. The most detailed analysis was made for the case of an A 3 B binary system with L1 2 superstructure [9], where the two time scales in "order-order" relaxations were attributed to an interplay between short-range (SRO) and long-range ordering controlled by "easy" B-antisite diffusion within the A-sublattice.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of atomic ordering in intermetallics

Oramus

Kozłowski

Kozubski

et al. 2004

Materials Science and Engineering: A

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“…Müller et al [21] reported that the disordering kinetics below room temperature are mainly based on the thermal spike model, while at elevated temperatures, the disordering and reordering processes occur simultaneously. Ewert et al [20] studied the reordering kinetics of irradiation-disordered Ni 3 Al and found that reordering at high temperatures is dominated by the motion of non-equilibrium vacancies. Liou et al [22] proposed a model to calculate the steady state of these two opposing processes (disordering and reordering) and concluded that the increased free energy of partially or fully disordered phases is sufficient to cause phase instability and modify the phase diagrams.…”

Section: Introductionmentioning

confidence: 99%

“…Irradiation-induced disordering of LRO precipitates is attributed to the creation of vacancies, interstitials and anti-site defects, which can disrupt the chemical and structural ordering of the precipitates [14][15][16][17][18]. However, as diffusion is enhanced, for example, by irradiation or thermal annealing, the disordered atoms tend to return to the equilibrium sites and the annihilation of defects can be promoted [12,19,20]. Müller et al [21] reported that the disordering kinetics below room temperature are mainly based on the thermal spike model, while at elevated temperatures, the disordering and reordering processes occur simultaneously.…”

Section: Introductionmentioning

confidence: 99%

Microstructure, chemistry and mechanical properties of Ni-based superalloy Rene N4 under irradiation at room temperature

Sun

Kirk

et al. 2015

Acta Materialia

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a b s t r a c tNickel superalloys with cubic L1 2 structured c 0 (Ni 3 (Al, Ti)) precipitates exhibit high strength at high temperatures and excellent corrosion resistance when exposed to water. Unlike prior studies on irradiation damage of other Ni-based superalloys, our study on Rene N4 involves much larger c 0 precipitates, $450 nm in size, a size regime where the irradiation-induced disordering and dissolution kinetics and the corresponding mechanical property evolution are unknown. We report that under heavy ion irradiation at room temperature, the submicron-sized c 0 precipitates were fully disordered at $0.3 dpa and only later partially dissolved after 75 dpa irradiation. Nanoindentation experiments indicate that the mechanical properties of the alloy change significantly, with a dramatic decrease in hardness, with irradiation dose. Three contributions to the change in hardness were examined: defect clusters, disordering and dissolution. The generation of defect clusters in the matrix and precipitates slightly increased the indentation hardness, while disordering of the submicron-sized c 0 precipitates resulted in a dramatic decrease in the total hardness, which decreased further during the early stages of the intermixing between c 0 precipitates and matrix (<18 dpa). Controlling the long-range-ordering and chemical intermixing can be used to tailor the mechanical properties of Ni-based superalloys under irradiation.

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Reordering kinetics of ion-disordered Ni Al

Cited by 14 publications

References 1 publication

Effect of He on the Order-Disorder Transition in Ni3Al under Irradiation

Effect of He on the Order-Disorder Transition in Ni3Al under Irradiation

Dynamics of atomic ordering in intermetallics

Microstructure, chemistry and mechanical properties of Ni-based superalloy Rene N4 under irradiation at room temperature

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