Precipitate stability in Cu–Ag–W system under high-temperature irradiation. (15th September 2015)

• Record Type: Journal Article
• Authors: Zhang, Xuan; Shu, Shipeng; Bellon, Pascal; Averback, Robert S.
• Is Part Of: Acta materialia. Volume 97(2015)
• Page Start: 348
• Page End: 356
• Publication Date: 2015-09-15
• Subjects: Self-organization -- Radiation-enhanced diffusion -- Radiation-enhanced precipitation -- Radiation damage; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2015.06.045
• Languages: English
• ISSNs: 1359-6454

Abstract

Graphical abstract: Abstract: The kinetics of precipitation was investigated in the ternary Cu alloy, Cu83.5 Ag15 W1.5 during irradiation with MeV Kr ions at elevated temperatures. The alloy was prepared as a solid solution by physical vapor deposition and then irradiated at room temperature to create a high density of nano-sized W precipitates. These precipitates served as effective sinks for point defects during subsequent elevated-temperature irradiation, suppressing radiation-enhanced diffusion. As a consequence the size of the Ag precipitates formed during elevated-temperature irradiation was stabilized below 20 nm, up to temperatures in excess of 300 °C, thus significantly extending the regime for "compositional patterning" above 175 °C, found for Cu85 Ag15 . For higher temperature irradiations (above 400 °C), the role of the W precipitates in stabilizing the size of the Ag precipitates switched from simply acting as point-defect sinks to serving as pinning sites for the Ag precipitates. At 500 °C, the average Ag precipitate diameter is ∼30 nm compared to ∼300 nm in the Cu85 Ag15 binary alloy. Rate theory calculations and kinetic Monte Carlo simulations are employed to illustrate how this transition takes place.