Effect of crystal orientation on the strengthening of iron micro pillars

Micro pillar compression testing has been performed on bcc iron single crystals to determine the mechanical properties and deformation mechanisms and their dependency on size and crystal orientation. Slip traces on the surface of post-compressed pillars were scrutinised to determine the operating slip system. The size dependency of the flow curves was investigated and the power law constants, K and n, and the orientation dependency of the resolved shear stresses were determined. ip trace analysis revealed that the slip follows the { 110 } 〈 111 〉 family of slip systems. The size dependency of the flow stresses follows the power law relation where the power law exponent n is in general between 0.5–0.8 and depend on orientation and the strain. The power law coefficient K increases as a function of strain. The shape is similar for the different loading directions, but varies in magnitude. The shear stress resolved to the ( 1 ¯ 01 ) [ 111 ] slip system shows an orientation dependent relation. Size and strain have little effect on this relation.