Enhancing radiation tolerance by controlling defect mobility and migration pathways in multicomponent single-phase alloys

Abstract

A grand challenge in material science is to understand the correlation between intrinsic properties and defect dynamics. Radiation tolerant materials are in great demand for safe operation and advancement of nuclear and aerospace systems. Unlike traditional approaches that rely on microstructural and nanoscale features to mitigate radiation damage, this study demonstrates enhancement of radiation tolerance with the suppression of void formation by two orders magnitude at elevated temperatures in equiatomic single-phase concentrated solid solution alloys, and more importantly, reveals its controlling mechanism through a detailed analysis of the depth distribution of defect clusters and an atomistic computer simulation. The enhanced swelling resistance is attributed to the tailored interstitial defect cluster motion in the alloys from a long-range one-dimensional mode to a short-range three-dimensional mode, which leads to enhanced point defect recombination. The results suggest design criteria for next generation radiation tolerant structural alloys.

Single-Phase Concentrated Solid-Solution Alloys: Bridging Intrinsic Transport Properties and Irradiation Resistance

“…(Yang et al, 2018). Unlike in Lu et al (2016b), no voids have been observed in both cases at all the test temperatures. For the observable defect clusters, the density decreases but the size increases with increasing irradiation temperature (Kumar et al, 2016;Yang et al, 2018).…”

“…FIGURE 7 | Cross-sectional TEM images for the void distributions in (a) Ni and (b) NiCoFeCr, and elemental distribution around (c) dislocations and (d) voids in NiCoFeCr, after 3 MeV Ni ion irradiations at 500 • C. Adapted from Lu et al (2016b) and Lu et al (2017). (Yang et al, 2018).…”

“…Note that irradiation temperature is a critical parameter for high temperature irradiation induced effects, e.g., swelling, and the temperature dependence varies with alloy compositions. The experimental studies till present primarily have focused either on one HEA at different irradiation temperatures (Kumar et al, 2016;Yang et al, 2018) or on the effects of compositional complexity at single irradiation temperature (Jin et al, 2016c;Lu et al, 2016b). How the number and species of principal alloying elements affect the temperature dependence of irradiation response in SP-CSAs requires future systematic studies.…”

“…In addition, interesting electrical transport properties such as superconductivity (Koželj et al, 2014) and quantum critical behavior (Sales et al, 2016(Sales et al, , 2017 have been discovered, and the HEAs have been considered promising in functional applications such as thermoelectric materials (Shafeie et al, 2015;Fan et al, 2016) and soft ferromagnetic materials (Zhang et al, 2013). Furthermore, recent studies have linked the mass and energy transport properties to the enhanced irradiation resistance (Zhang et al, 2015;Lu et al, 2016b;Zhang Y. et al, 2017). Different from the traditional design strategies of irradiation tolerant alloys that usually introduce extrinsic defect sinks, such as grain boundary, secondary phases, and nano particles (Ukai and Fujiwara, 2002;Was, 2007;Garner, 2012), HEAs allow the focus on the effects of intrinsic properties determined by the major alloying elements on irradiation response, as considered a new path of designing radiation resistant alloys.…”

Local Structure and Short-Range Order in a NiCoCr Solid Solution Alloy

“…As a new class of materials, these compositionally complex alloys have attracted a large number of research interests over the past decade, leading to the discovery of some excellent mechanical properties and interesting physical properties [3][4][5][6][7][8][9][10]. Recently, many multicomponent solid solution alloys with 3d transition elements from Cr to Ni in the periodic table, which have similar atomic size, have been synthesized and all of these Ni-based alloys have a simple face-centered cubic (fcc) structure [10][11][12][13][14].…”