Publications by authors named "Seong Man Choi"
We studied a candidate TPS (thermal protection system) material for reusable re-entry space vehicle applications. The material was based on a high-temperature-resistant material called Cerakwool. A total of six specimens were fabricated with substrate densities of 0.
View Article and Find Full Text PDFWe studied the behavioral characteristics of a newly developed dual-layer ablator, which uses carbon-phenolic as a recession layer and silica-phenolic as an insulating layer. The ablator specimens were tested in a 0.4 MW supersonic arc-jet plasma wind tunnel, employing two different shapes (flat-faced and hemispherical-faced) and varying thicknesses of the carbon-phenolic recession layer.
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- * The ablators underwent testing in a high-powered supersonic arc-jet plasma wind tunnel, simulating heat conditions similar to a spacecraft's atmospheric re-entry, with tests lasting up to 110 seconds.
- * Results showed that the silica-phenolic-insulated specimens remained stable during testing, keeping internal temperatures below 450 K (~180 °C), which was the main goal of the study.
Article Synopsis
- The study focused on ablation experiments of carbon phenolic materials and specially designed SiC-coated composites to evaluate their performance as thermal protection systems (TPS) for future spacecraft.
- Testing involved varying heat flux conditions (3.25 to 11.5 MW/m) and used advanced measurement techniques to monitor temperature responses in the materials.
- Results indicated that the 30° carbon phenolic specimen outperformed the SiC-coated graphite base in terms of lower internal temperatures and fewer abnormal behaviors, making it a more suitable choice for TPS applications.
To improve the oxidation resistance of carbon composites at high temperatures, hafnium carbide (HfC) and titanium carbide (TiC) ultra-high-temperature ceramic coatings were deposited using vacuum plasma spraying. Single-layer HfC and TiC coatings and multilayer HfC/TiC coatings were fabricated and compared. The microstructure and composition of the fabricated coatings were analyzed using field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy.
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