Abstract
There is an increasing necessity to record the deformation characteristics of microelements often consisting of freestanding foils and wires. The data required are either mechanical or thermal such as Young`s moduli, stress-strain values, fatigue- and thermal strain data, but the nominal strength of a structure changes by scaling its size. Due to this size effect, material data cannot be taken from macrospecimens, thus special testing procedures were introduced. Laseroptical sensors based on the speckle correlation method were applied to determine non-contacting strain values with high strain resolution. For the mechanical properties tensile tests were used for the freestanding foils and wires. For thermal strain measurements a laser speckle based dilatometer was designed. A short outline of applicability of the testing equipment is given. The following materials data are presented and discussed: Young`s modulus, mechanical and thermo-mechanical and thermal strain data of various Cu foils and wires with varying grain sizes, thickness and defined texture. A thickness effect was detected and is interpreted in terms of a "thickness to grain size ratio" approach.
