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AlCoCrFeNi high-entropy alloys (HEAs) were prepared by Bridgman solidification with different solidification rates, and the mechanical behavior of the HEAs was investigated over a wide strain rate range (³10 ¹3 ³10 3 s ¹1). Microstructure observations suggest that, with increasing solidification rate, the microstructure evolves from coarse columnar grains to fine equiaxed ones. Through compression tests under both quasistatic and dynamic strain rates, the AlCoCrFeNi HEAs were found to possess positive strain-rate sensitivity (SRS), and the HEA with lower solidification rate exhibits higher SRS, which are attributed to the coarse grain size.

Abstract. The microstructure and mechanical properties of 0Cr21Ni6Mn9N austenitic stainless steel cold drawn pipe were investigated at various annealing temperatures. It was found that the tensile strength and the yield strength increased slightly, and then decreased with the temperature increasing from 200 to 750 °C. The highest value of tensile strength and yield strength reached 1062 and 942MPa at 600 °C, respectively. However, the elongation has an opposite trend to the tensile strength and yield strength. The microstructure evolution of the cold drawn pipe annealed at different temperatures was observed. The results indicate that when annealed below 550 °C, recovery is dominant. At 550 °C, it is recovery and partial recrystallization. Over 550 °C, complete recrystallization has likely occurred. Moreover, the Cr 2 N particles near the grain boundaries were found, and the amount of precipitates along the grain boundary indexed as M 23 C 6 were increasing at 650-800 °C.