[T19] High Entropy Alloys

[14D-T19-06] Hetero-Deformation-Induced (HDI) Softening of a Harmonic Structure Designed CrMnFeCoNi Alloy Compact at Elevated Temperatures

*H. Kawano¹, S. Hosogi¹, M. Kawabata², H. Fujiwara¹, K. Ameyama¹ (1.Ritsumeikan University, Japan, 2.Ritsumeikan Global Innovation Research Organization, Japan)

キーワード：HDI strengthening, compression test, strain rate sensitivity, pseudo-superplasticity

Hetero-Deformation-Induced (HDI) strengthening is the important key to the strengthening mechanism in heterogeneous structure materials that exhibit both strength and ductility simultaneously. In the Harmonic Structure (HS) materials, high strength and high ductility are also simultaneously exhibited in the same manner via the HDI strength at room temperature. In the present study, a high entropy CrMnFeCoNi alloy with homogeneous and harmonic structures were subjected to high temperature compression tests at different strain rates. As a result, the HS designed specimen showed a significant reduction in flow stress compared to the homogeneous structure counterpart. In addition, the homogeneous specimens had a strain rate sensitivity value of less than 0.3, while the HS specimens had a strain rate sensitivity value greater than 0.3, such as 0.541 at 1173K. In other words, the HS specimens exhibited pseudo-superplastic deformation, i.e. Hetero-Deformation-Induced (HDI) softening.