Tensile properties of thin Cu-wires with a bamboo microstructure

Displacement controlled tensile tests have been performed on high purity Cu wires of thickness 20, 50 and 125?m in bamboo grain structure making use of a laser speckle extensometer. Scanning electron micrographs of the wire surface after fracture revealed large grains deformed in single slip, in double slip, undeformed ones, and sample parts which have remained fine grained being nearly undeformed. Stress-strain curves of the deformed material are obtained inserting the sample length being active in deformation. They are discussed with respect to single crystal deformation curves of bulk wires. The comparably smaller fracture strains can be explained from surface inhomogeneities by wire drawing and slip steps. Π2004 Elsevier B.V. All rights reserved.