249 / 2023-04-20 15:43:07

The deformation and damage mechanism of different kinds of high-entropy alloy with various microstructures under shock compression

高压物理与材料科学 > 动高压-I

With the development of the frontier of the science and the demands of the national major strategic, the defense industry and aerospace field have put forward increasingly stringent requirements for the performance of metal materials under extreme conditions, such as high temperature, high pressure and high strain rate. Previous conventional alloys which are composed of one or two principal elements like steel, magnesium alloy, and aluminum alloy could not satisfy the needs of such complex applications. Thus, multiple principal element alloys (including medium entropy alloy and high entropy alloy) emerge. Currently, the mechanical properties and deformation mechanism of various kinds of high entropy alloys have been extensively under quasi-static or split Hopkinson pressure bar loading. In order to understand and predict the service behavior of high-entropy alloys with different microstructures under extreme conditions, in this study, plate impact experiments are conducted on single face-centered cubic Al_0.1CoCrFeNi, single body-centered cubic HfZrTiTa_0.53, heterogeneous-structured CrMnFeCoNi, metastable dual-phase Cr₁₀Mn₃₀Fe₅₀Co₁₀, eutectic AlCoCrFeNi_2.1 and dendritic dual phase CoCrFeNiCu. Free surface velocity histories are obtained along with microstructure characterizations. The impact properties including the Hugoniot elastic limit (HEL) and dynamic tensile fracture (spall) strength as well as underlying deformation mechanisms (dislocations, stacking faults, deformation twins and phase transition) and damage modes are obtained. A systematic investigation of these different kinds of high-entropy alloy with various microstructures will help to evaluate the impact performance and improve materials design of high entropy alloys.