연소시험에서 산소와 연료 비에 따른 탄화규소로 코팅된 탄소/ 탄소 복합재의 삭마 메커니즘

장은희; 김정백; 주혁종; Eun-Hee Zhang; Zeong-Baek Kim; Hyeok-Jong Joo

Journal of the Korean Industrial and Engineering Chemistry, Vol.18, No.3, 227-233, June, 2007

Export Citation

연소시험에서 산소와 연료 비에 따른 탄화규소로 코팅된 탄소/ 탄소 복합재의 삭마 메커니즘

Ablative Mechanism of SiC Coated Carbon/carbon Composites with Ratio of Oxygen to Fuel at Combusion Test

장은희, 김정백¹, 주혁종 ^{1, †}

금호석유화학 중앙연구소
¹충남대학교 고분자공학과

Eun-Hee Zhang, Zeong-Baek Kim¹, and Hyeok-Jong Joo^{1, †}

Resin Application Team, Kumho Petrochemical R&BD Center, Daejeon 305-348, Korea
¹Department of Polymer Science and Engineering, Chungnam National University, Daejeon 305-764, Korea

E-mail:

초록

탄소/탄소 복합재는 우수한 열충격 저항성, 낮은 밀도뿐만 아니라, 초고온에서도 높은 강성과 강도를 가지는 독특한 소재이다. 그러나, 탄소/탄소 복합재의 적용에 있어서 심각한 결함이 있는데, 높은 온도에서 산화되는 환경에서는 취약한 산화 저항을 나타낸다는 것이다. 탄화규소 코팅은 탄소재의 산화를 보호하는데 이용된다. 본 연구에서는 4방향성 탄소/탄소 복합재의 삭마 거동을 시험하기 위해 액체연료 로켓 엔진을 사용하여 연소시험을 하였다. 탄소/탄소 복합재는 기지 전구체로 석탄 핏치를 사용하였고, 2300 ℃에서 열처리 하였다. 고밀도화 과정을 반복하여 시편의 밀도는 1.903 g/cm3에 달했다. 4방향성 탄소/탄소 복합재를 노즐 형태로 가공한 후, 산화 저항성을 개선하기 위하여 pack-cementation 방법으로 노즐 표면에 탄화규소를 코팅하였다. 탄화규소로 코팅된 노즐의 삭마 특성은 연료와 산소의 비율에 따라 측정하였다. 또한 연소시험 후 노즐의 삭마된 현상은 주사전자현미경으로 관찰하고, 삭마 메커니즘을 논의하였다.

Carbon/carbon (C/C) composites as unique materials possess exceptional thermal resistance with light weight, high stiffness, and strength even at high temperature. However, one serious obstacle for application of the C/C composites is their poor oxidation resistance in high temperature oxidizing environments. SiC coating has been employed to protect the composites from oxidation. This study explored combustion characteristics of 4-directional (4D) carbon/carbon composites using liquid fuel rocket engine to investigate ablative motion of the materials. C/C composites were made of coal tar pitch as a matrix precursor, and heat-treated at 2300 ℃. Throughout repeated densification process, the density of the material reached 1.903g/cm3. After machining 4D C/C composites, the nozzle surface was coated by a SiC layer by pack-cementation method to improve oxidation resistance. Erosion characteristics of SiC-coated C/C composites were measured as function of the ratio of oxygen to fuel. The morphological change of the composites after combustion test was investigated using SEM and erosion mechanism also was discussed.

Keywords:carbon/carbon composites;SiC coating;ablative behavior;combustion test;rocket motor nozzle

[References]

Huzel DK, Huaang DH, Modern Engineering For Design of Liquid-Propellant Rocket Engines, AIAA Publ., 147, Prog. in Astronautics and Aeronautics, Washington DC (1992)
Sheehan JL, Carbon, 27, 709 (1989)
Jone LE, Thrower PA, Carbon, 29, 251 (1991)
Fitzer E, Carbon, 25, 163 (1987)
Lamicq PJ, International Carbon Conference, Bordeaux, France (1984)
Lee YJ, Joo HJ, Investigation on ablation behavior of CFRC composites prepared at different pressure, Composite: part A, 35, 1285 (2004)
Lee YJ, Joo HJ, Surf. Coat. Technol., 180, 286 (2004)

[Related Articles]

[1] Huzel DK, Huaang DH, Modern Engineering For Design of Liquid-Propellant Rocket Engines, AIAA Publ., 147, Prog. in Astronautics and Aeronautics, Washington DC (1992)

[2] Sheehan JL, Carbon, 27, 709 (1989)

[3] Jone LE, Thrower PA, Carbon, 29, 251 (1991)

[4] Fitzer E, Carbon, 25, 163 (1987)

[5] Lamicq PJ, International Carbon Conference, Bordeaux, France (1984)

[6] Lee YJ, Joo HJ, Investigation on ablation behavior of CFRC composites prepared at different pressure, Composite: part A, 35, 1285 (2004)

[7] Lee YJ, Joo HJ, Surf. Coat. Technol., 180, 286 (2004)