Effects of Strain Rate on Tensile Properties of Copper and α-Iron Single Crystals of Miniaturized Specimen

Abstract

The effect of strain rate on tensile properties of copper and α-iron single crystals was investigated at room temperature by a static tensile testing on miniaturized rectangular specimens. Micro-polished rectangular tensile specimens were subjected to uniaxial stress with a constant strain rates up to their fracture point. The tensile strength increased with strain rate for both materials. The yield strength decreased substantially for copper single crystals but increased with an increase in the strain rate for α iron single crystals when the strain rate exceeded 1x10-2 s-1. In copper samples ductility increased with an increase in the strain rates. For α-iron a higher ductility was observed at the lowest strain rate. The post-necking elongation of both materials showed a linear relationship with the strain rate. The effect of strain rate on tensile deformation properties of copper and α-iron miniaturized specimens were somehow in good agreement to those observed in previous studies at nano-levels and macro-levels.