The Bauschinger effect in thin sputter-deposited Al and Cu films is studied by isothermally deforming the films alternately in tension and compression. Passivated films exhibit an unusual Bauschinger effect with reverse flow already occurring on unloading, while unpassivated films show little or no reverse flows when the film is fully unloaded. 2005 Acta Materialia Inc. Published by Elsevier Lt...

Large diameter steel line pipes are generally produced by cold deforming hot rolled or thermomechanically controlled rolled (TMCR) plate by the three-stage 'UOE' process. Pipe strength has been found to increase or decrease relative to the plate, depending on the steel grade and plate processing history. The strength increase is due to work hardening whereas any decrease in strength arises from...

Conventionally, mean grain size is considered the most critical microstructural parameter in determining the mechanical behavior of pure metals. By systematically controlling the distribution of grain orientations in aluminum films, we show that microstructural heterogeneity alone induces large variation in the mechanical behavior of nanocrystalline metal films. Aluminum films with relatively h...

The plasticity of micron scale Cu and Au wires under cyclic torsion is investigated for the first time by using a torsion balance technique. In addition to a size effect, a distinct Bauschinger effect and an anomalous plastic recovery, wherein reverse plasticity even occurs upon unloading, are unambiguously revealed. The Bauschinger effect and plastic recovery have been observed in molecular dy...

Ultrafi ne grained (UFG) and nanocrystalline (NC) metals, unlike coarse-grained metals, often show inelastic strain recovery during unloading, which is referred to as early Bauschinger effect. Several experimental and simulation studies have focused on the microscopic origins of this unusual mechanical behavior. However, the strain rate dependence of early Bauschinger effect in UFG and NC metal...

Experimental measurements and computational results for the evolution of plastic deformation in freestanding thin films are compared. In the experiments, the stress–strain response of two sets of Cu films is determined in the plane-strain bulge test. One set of samples consists of electroplated Cu films, while the other set is sputter-deposited. Unpassivated films, films passivated on one side ...