Material Characterization at High Strain Rates with Special Emphasis on Miniaturization and Size Dependencies

Abstract

Within the present work the size-dependent flow stress and failure behaviour of various metallic materials is described. Starting with special issues of testing miniaturized specimens, the influence of manufacturing routes and manufacturing induced geometrical deviations is investigated. The specimen size and time-dependent flow stress behavior of C45E, Ti-6-22-22S, and Al7075T6 is presented. The measured behavior is explained by size-dependent friction effects. Additionally, the influence of size and time scaling on the occurring of failure is investigated. A decrease of compressive deformability with increasing size and strain rate was found. The consideration of a size-dependent thermodynamic process character provides a possible explanation for measured size dependencies.