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The impact behaviors of as-cast body-centered-cubic (BCC)-structure TiVTa and TiVTaNb refractory single-phase concentrated solid solution alloys were studied under impact loading as part of an effort to evaluate their potential application in the nuclear field as structural materials. Instrumented Charpy impact tests and fractography analysis showed that TiVTaNb demonstrated a relatively higher ductility with a higher total impact absorbed energy, higher shear-rips proportion, lower ductile–brittle transition temperature (DBTT) and higher upper shelf energy (USE) than that of TiVTa from − 150°C to 550°C. Analysis of load–displacement curves revealed that the crack initiation and propagation energy of TiVTaNb is larger than that of TiVTa, showing the higher resistance to crack initiation and propagation in TiVTaNb. This study demonstrates that the TiVTaNb is a promising ductile material for structural applications. [ABSTRACT FROM AUTHOR]

Rate theory (RT) is a commonly used method to simulate the evolution of material defects. A promising numerical method, exponential time difference (ETD), can reduce the stiff RT equations to explicit ordinary differential equations (ODEs). Previous implementations of ETD on the "Sunway TaihuLight" supercomputer suffer from high computation cost and poor parallel efficiency while solving a large amount of ODEs. This paper improves the algorithm with hybrid MPI+SIMD and additional instruction-level optimizations by taking advantage of the architecture of "Sunway TaihuLight". The execution time of a single iteration is reduced by about 40%. Scaling from 64 to 4096 processes, the parallel efficiency of the new algorithm achieves 33.5% and 50.6% in strong and weak scalability, which corresponds to 21.4 and 32.4 in speedup, respectively. [ABSTRACT FROM AUTHOR]

The effects of irradiation on chromium performance under different temperatures in Fe-20at%Cr were modeled by modified Marlowe code. Chromium precipitation was observed in FeCr alloy after irradiation; interstitial Chromium atoms are the preferred formation of mixed Fe-Cr dumbbells in the direction of <110> and <111>; interstitial chromium atoms congregated on {111} and {110} plane. The results are compared with experiment observations and are useful to understanding the irradiation performances of FeCr alloy. [ABSTRACT FROM AUTHOR]