Influence of inclined twin boundaries on the deformation behavior of Cu micropillars

In situ micromechanical compression tests on Cu pillars were performed to evaluate the influence of twin boundaries on the mechanical behavior. The 1 µm sized Cu samples on a Si substrate prepared by focused ion beam milling were either single crystalline or contained 2-5 twin boundaries that were inclined to the compression direction. The strengths of the pillars vary, depending on the crystal orientation, associated twin boundary inclination and orientation of slip systems. Results show, that multiple slip systems are activated in each pillar. However, slip parallel to the twin boundaries prevails due to the long mean free path for dislocation movement.