| Abstract |
| This study investigates the effects of porosity on the thermal stability and the thermal shock resistance of a porous nozzle used for blowing an inert gas. The samples of Al2O3-SiO2-ZrO2 system, which had the apparent porosity of 16~30% and bulk density of 2.6~3.2 g/cm3, were prepared by adding different graphite contents (5, 10, 20 wt%) as a pore-forming agent. The thermal shock test was conducted at ΔT=500, 1000, and 1400℃ also and the thermal stability was also carried out at 1550, 1600, and 1650℃ for 5 hrs. The specimen contained 10 wt% graphite had uniform pore size distribution, whereas the specimen with 20 wt% graphite showed non-uniform pore size distribution. As a result of thermal shock test, the specimen containing 10 wt% graphite appears to have higher mechanical strength than the other specimens (5, 20 wt% graphite). Both the 5 wt% and 20 wt% graphite specimens developed a non-uniform pore size distribution and cracks that were generated by intensive thermal stress. |
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| Key Words |
| porous materials, sintering, microstructure, scanning electron microscopy, SEM, durability |
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