LAUSR

This work demonstrates a novel approach to ultrahigh temperature mechanical testing using a combination of in situ nanomechanical testing and localized laser heating. The methodology is applied to characterizing and testing initially nanograined 10 mol% Sc2O3-stabilized ZrO2 up to its melting temperature. The results suggest that the low temperature strength of nanograined, d < 50 nm, oxides is not influenced by creep. Tensile fracture of ZrO2 bicrystals produce a weak temperature dependence suggesting that grain boundary energy dominates brittle fracture of grain boundaries even at high homologous temperatures; e.g. T = 2050 °C or T≈ 77%Tmelt. The maximum temperature for mechanical testing in this work is primarily limited by the stability of the sample, i.e. evaporation or melting, enabling a host of new opportunities for testing materials in the ultrahigh temperature regime.