Creep Micromechanics in Meso-Length Scale Samples

This study focuses on the creep response of meso-length scale systems, whose smallest dimensions lie in range a few hundred micrometers to millimeters. Here, uniaxial experiments were performed commercially pure Al polycrystals using samples having (or, characteristic sample) dimension 500 μm 7 mm “five”-power law regime. Compared interior, near-surface region developed compliant dislocation substructures, marked by lower density and larger subgrain size. Furthermore, extent this surface-affected (SAR) inversely varied with applied stress was limited grain As SAR became comparable sample (CSD), material significantly affected “weaker” surface, thereby reducing overall resistance. also resulted decrease exponent CSD. The differential resistance surface interior leads load-shedding between “weak” “strong” interior. A microstructure-sensitive iso-strain composite model quantifying effect formulated explain observed across various length scales. critical insights into micro-mechanics obtained study, therefore, seamlessly unify power-law at large small