Mechanical Characterisation of Carbon-Bonded Magnesia at Temperatures up to 1400 degrees C

摘要

The mechanical properties of carbon-bonded magnesia were investigated from room temperature to 1400 degrees C in tension, compression and bending. For this purpose, quasi-static, static and cyclic tests were conducted on two testing machines, equipped with inert atmosphere chambers and inductive heating devices. Characterisation of the microstructure was performed with scanning electron microscopy (SEM) and optical microscopy (OM). Porosity and density were measured with the Archimedes principle and pycnometry. From the creep tests, activation energies and Norton exponents for high -temperature creep deformation were determined. Additionally, scatter was addressed. The cyclic tests showed a high influence of stress amplitude on fatigue lifetime, whereas degradation of specimens only took place in tension.