Ni Ti shape memory alloys –
New materials investigated with the powerful method of DMTS -
Tensile clamping device

The picture shows modulus E‘ and the loss factor tan delta of a Ni Ti wire (shape memory alloy) in function of temperature. With increasing temperature (heating rate: 3 °C/min, test frequency: 10 Hz) the shape memory alloy undergoes the transformation from the martensite to the austenite at a material specific transition temperature. At the transition temperature a sudden increase of the tensile modulus E‘ as well as a decrease of the intrinsic visco-elastic damping tan delta is observed.

Temperature dependence of magnesium
Modified single cantilever device

The figure shows the storage modulus E‘ and the loss factor tan delta of a magnesium bar (thickness: approx. 2 mm, height: approx. 4 mm) in function of the temperature. With increasing temperature (heating rate: 2 °C/min, test frequency: 10 Hz) the modulus decrease softly about 20 %. The intrinsinc damping shows a significant increase with rising temperature. A strong increase for tan delta about five magnitudes of order on a log scale has to been noticed. This run shows the very high resolution in tan delta measurement due to the very high resolution and accuracy of the test instrument EPLEXOR®.