Effects of minor Nb alloying on the thermal stability and mechanical responses of a γ/γ′ type high-entropy alloy with high Fe content
Effects of minor Nb alloying on the thermal stability and mechanical responses of a γ/γ′ type high-entropy alloy with high Fe content
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DOI：
10.1016/j.msea.2022.143610
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发表时间：
2022-07
期刊：
影响因子：
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通讯作者：
Junyang He;N. Li;S. Makineni;Y. Zhao;Wei-hong Liu;Li Wang;Zhangwei Wang;Min Song
中科院分区：
文献类型：
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作者：
Junyang He;N. Li;S. Makineni;Y. Zhao;Wei-hong Liu;Li Wang;Zhangwei Wang;Min Song
In this work, by equipping the high-entropy concept we designed a γ/γ′-type high-entropy alloy with high Fe content (25 at.%), and further alloyed Nb to evaluate its microstructural stability and mechanical responses. We found that after 850 °C annealing, 1.5 at.% Nb addition can completely suppress the discontinuous precipitation (DP) reaction. The high γ/γ′ structural stability even after one month ageing at 800 °C is believed to be originated from strong partitioning of Nb to γ′. The onset of continuous inter-mass-flow of Fe and Nb across the γ/γ′ interface further enhances the γ′ ripening resistance. The increased tensile strength in the Nb-alloyed HEA across a wide temperature range (23–900 °C) is because of the increased volume fraction and anti-phase boundary energy of γ′. The corresponding lowered ductility is then attributed to the absence of the DP colony that not only acts as a stress buffer zone but also introduces grain boundary serration to withstand intergranular cracking.
