Influence of Grain Interaction on the Mechanical Behavior in Shape Memory Material in Flexion Test

An experimental study of the mechanical properties of a Cu-Al-Be shape memory alloy is presented. The samples are tested in a cantilever arrangement. They consist of polycrystalline thin plates of shape memory material with a MS near 0 °C and a monocrystalline sample with MS near -90 °C. The measurements are made with strain gauges attached to the top side of the samples. In these conditions, strain Vs load curves are obtained. A polycrystalline sample is instrumented and tested and then it is cut into three samples for further testing. The results show a relationship between the transformation stress and the sample grain size which differs from the typical Hall-Petch relationship. The analysis of transformation plane stress diagrams shows the development of a stress component perpendicular to those induced by the applied load.