2023/03/16 by Ning Fang, Yang Liu, Fang, Ning +5
Engineering · Materials Science · #FOS: Physical sciences #High-Velocity Impact and Material Behavior #Materials Science (cond-mat.mtrl-sci) #Metallurgy and Material Forming #Microstructure and mechanical properties
paper · pdf · doi:10.48550/arxiv.2303.09600
openalex publication_date 2023/03/16 · openalex created_date 2023/03/21 · openalex updated_date 2026/07/28
The slip strength of individual slip systems at different strain rates will control the mechanical response and strongly influence the anisotropy of plastic deformation. In this work, the slip activity and strain rate sensitivity of the basal, prismatic, and pyramidal slip systems are explored by testing at variable strain rates (from 10E-4 s-1 to 125 s-1) using single crystal micropillar compression tests. These systematic experiments enable the direct fitting of the strain rate sensitivities of the different slips using a simple analytical model and this model reveals that deformation in polycrystals will be accommodated using different slip systems depending on the strain rate of deformation in addition to the stress state (i.e. Schmid's law). It was found that the engineering yield stress increases with strain rate, and this varied by slip systems. Activation of the prismatic slip system results in a high density of parallel, clearly discrete slip planes, while the activation of the pyramidal slip leads to the plastic collapse of the pillar, leading to a 'mushroom' morphology of the deformed pillar. This characterization and model provide insight that helps inform metal forming and understanding of the mechanical performance of these engineering alloys in the extremes of service conditions.