Evaluating strength at ultra-high temperatures—Methods and results

Proprietary equipment for mechanical testing at ultra-high temperatures by ohmic heating is outlined. Strain is measured with a video extensometer with an accuracy of up to Δ ε ¯ ≈ ± 0.00025 % . Stability and accuracy of the test system are evaluated on Pt- and refractory alloys. These specially designed and built test facilities are compared to commercially available high-vacuum test chambers with tungsten heater.