Methodical features of the measurement of mechanical properties of ultrafine-grained materials

The effects of methodical factors, namely, the geometry and shape of microspecimens and also the type of the testing machine on the mechanical properties of commercial ultrafine-grained titanium during tensile testing in comparison with those of a coarse-grained material have been investigated. It has been shown that the strength and ductility of microspecimens with an ultrafine-grained structure are more sensitive to changes in their shape and geometrical size. A distinctive role of the width-to-thickness ratio, which is responsible for the type of the stress-strain state during tensile deformation of a flat specimen, has been discussed.