| Title |
Effects of Porosity on Durability in a Porous Nozzle for Continuous Casting |
| Authors |
윤상현(Sang Hyeon Yoon); 이희수(Hee Soo Lee); 조문규(Mun Kyu Cho); 정두화(Doo Hoa Jeong) |
| DOI |
https://doi.org/10.3365/KJMM.2010.48.07.625 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
porous materials; sintering; microstructure; scanning electron microscopy; SEM; durability |
| 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. |