Medium entropy alloy-induced strong size dependence in the strengthening and shear instability of nanolayered metallic composites

Qin，Feng1,2; Dai，Kaiqing1; Hou，Junhua3; Lu，Wenjun3; Chen，Shaohua4; Li，Jianjun1,2

2024-10-01

10.1016/j.mechmat.2024.105107

Mechanics of Materials   影响因子和分区

0167-6636

Medium/high entropy alloys (M/HEAs)-based nanolayered metallic composites have attracted intensive scientific interests due to their superior mechanical properties. However, the shear instability of the M/HEAs-based composites is rarely studied and the underlying mechanism remains uncovered. A combination of theoretical analysis and nano/microindentation tests was conducted to investigate the size-dependent strengthening and shear instability of Cu/CrCoNi composites. The results show that the shear banding-induced instability of the composites exhibit a clear transition from layer interfaces-mediated kinking to grain boundaries-accommodated one at a critical layer thickness of 25 nm, which apparently differs from those in traditional M/HEAs-free composites. The sudden change in the deformation mode originates from the MEA-induced size-dependent microstructure transformation, i.e., from horizontally aligned layer interfaces at large layer thicknesses to vertically aligned grain boundaries at small ones. The size-dependent strengthening and plasticity can be respectively captured by the confined layer slip model and the proposed theoretical model.

Interfaces Medium entropy alloys Nanolayered metallic composites Shear instability Strengthening

SCI ; EI

英语

其他

MATERIALS SCIENCE

2-s2.0-85200133072

Scopus

1.College of Mechanical and Electrical Engineering,Central South University,Changsha,Hunan,410083,China
2.State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,Changsha,Hunan,410083,China
3.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China
4.School of Aerospace Engineering,Beijing Institute of Technology,Beijing,100081,China

Qin，Feng,Dai，Kaiqing,Hou，Junhua,et al. Medium entropy alloy-induced strong size dependence in the strengthening and shear instability of nanolayered metallic composites[J]. Mechanics of Materials,2024,197.

Qin，Feng,Dai，Kaiqing,Hou，Junhua,Lu，Wenjun,Chen，Shaohua,&Li，Jianjun.(2024).Medium entropy alloy-induced strong size dependence in the strengthening and shear instability of nanolayered metallic composites.Mechanics of Materials,197.

Qin，Feng,et al."Medium entropy alloy-induced strong size dependence in the strengthening and shear instability of nanolayered metallic composites".Mechanics of Materials 197(2024).