Development of a high-temperature micromechanics stage with a novel temperature measurement approach

The study of mechanical properties of materials at high temperatures at the microstructural length regime requires dedicated setups for testing. Despite the advances in the instrumentation in these setups over the last decade, further optimization is required in order to extend the temperature range well-beyond 600 °C. Particularly, an improvement of the contact temperature measurement is required. A design with a novel approach of temperature measurement with independent tip and sample heating is developed to characterize materials at high temperatures. This design is realized by modifying a displacement controlled room temperature microstraining rig with the addition of two miniature hot stages, one each carrying the sample and indenter tip. The sample reaches temperatures of >600 °C with a 50 W diode laser system. The stages have slots for the working sample as well as a reference sample on both ends for precise temperature measurements, relying on the symmetry of the stage toward the ends. The whole setup is placed inside a custom-made steel chamber, capable of attaining a vacuum of 10⁻⁴ Pa. Alternatively, the apparatus can be operated under environmental conditions by applying various gases. Here, the unique design and its high temperature capabilities will be presented together with the first results of microtension experiments on freestanding copper thin films at 400 °C.