Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
권호 표지

Analysis of Thermal Conductivities of Carbon/Phenolic and Silica/Phenolic Ablative Composites by Laser Pulse Method

레이저 섬광법을 이용한 Carbon/Phenolic 및 Silica/Phenolic 내열복합재료의 열전도도 분석

  • 김희영 (한국과학기술원 재료공학과) ;
  • 김평완 (한국과학기술원 재료공학과) ;
  • 홍순형 (한국과학기술원 재료공학과) ;
  • 김연철 (국방과학연구소) ;
  • 예병한 (국방과학연구소) ;
  • 정발 (국방과학연구소)
  • Published : 1999.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

The thermal properties of carbon/phenolic and silica/phenolic ablative composites were investigated by measuring the heat capacity, thermal diffusivity and thermal conductivity. The heat capacities of carbon/ phenolic and silica/phenolic composites were calculated from differential scanning calorimeter curve. The thermal diffusivities of carbon/phenolic and silica/phenolic composites were measured by the laser flash method with varying laminated direction, i.e., with laminar direction and across laminar direction. The thermal diffusivities decreased with increasing temperature. The thermal conductivities of carbon/phenolic and silica/phenolic composites were calculated using the heat capacity, density and thermal diffusivity. The thermal conductivities increased with increasing temperature. The thermal conductivity of with laminar direction is two times higher than that of across-laminar direction in carbon/phenolic composite due to the directionality of thermal conductivity of carbon fiber. The thermal conductivities of two dimensional fiber reinforced composites were analyzed using the conductivities of constituents and volume fraction of each constituent. The thermal conductivities of carbon fiber and silica fiber were calculated from thermal conductivities of carbon/phenolic and silica/phenolic composites. The thermal conductivities of carbon/phenolic and silica/phenolic composites at RT were predicted from thermal conductivities of fiber and resin with varying the volume fraction of fiber.

Carbon/Phenolic 및 silica/phenolic 내열 복합재료의 강화재의 종류와 적층방향에 따른 비열, 열확산 계수, 열전도도를 분석하였다. Carbon/Phenolic 및 silica/phenolic 복합재료의 비열은 시차 주사 열량법을 이용하여 측정하였으며, 열확산계수는 레이저 섬광법을 이용하여 laminar와 평행방향과 laminar와 직교방향으로 측정하였다. Carbon/Phenolic 및 silica/phenolic 복합재료의 열확산계수는 온도가 증가함에 따라 감소하였다. Carbon/Phenolic 및 silica/phenolic 복합재료의 열전도도를 밀도, 열확산계수 및 비열을 이용하여 계산하였다. 열전도도는 온도가 증가함에 따라 증가하였으며, carbon/Phenolic의 경우 laminar와 평행방향의 열전도도가 laminar와 직교방향의 열전도도보다 2배 높은 이방성을 나타내었으며 이는 carbon 섬유의 열전도도 이방성 때문으로 해석되었다. 이차원 섬유강화 복합재료의 열전도도를 기지와 강화재의 열전도도와 부피분율을 이용하여 해석하였다. Carbon/Phenolic 및 silica/phenolic 복합재료의 열전도도를 적층방향에 따라 강화재와 기지의 열전도도를 이용하여 해석하여 carbon 섬유와 silica 섬유의 열전도도를 계산하였다. 계산된 섬유의 열전도도와 기지의 열전도도로부터 섬유의 부피분율에 따른 복합재료의 상온열전도도를 예측할 수 있었다.

Keywords

References

  1. Ablative Plastics for Re-entry Thermal Protection, WADD TR 60-862, USAF ASD Schmidt, D. L.
  2. Environmental Effect on Polymeric Materials Schmidt, D. L.
  3. Rocket Propulsion Elements Sutton, G. P.;Ross, D. M. Rocket
  4. J. Advanced Materials v.28 no.2 High Temperature Properties of Ablative Composite-I Weisshaus, H.;Engleberg, I.
  5. High-temperature properties of some reinforced phenolic composites v.12 Goetzel, C. G.
  6. Effect on Ablation on Thermal Conductivity to 5000R in Phenolic-Carbon and Phenolic-Graphite, Technical Report AFML-TR-67-413 Clayton, W. A.;Fabish, T. J.
  7. J. Thermophysics and Heat Transfer v.9 no.2 Kinetics of Pyrolysis Mass Loss from Cured Phenolic Resin Stokes, E. H.
  8. Rev. Int. Hautes Temp. et Refract. v.7 Multiproperty Apparatus and Procedure for High Temperature Determinations Powell, R. W.;Taylor, R. E.
  9. J. Appl. Phys. v.32 Flash Method of Determining Thermal Diffusivity, Heat Capacity and Thermal Conductivity Paker, W. J.;Jenkins, C. P.;Butter, C. P.;Annott, G. L.
  10. Thermographic Investigation of Laser Flash Diffusivity Measurement v.19 Arai, T.;Baba, T.;Ono, A.
  11. ASTM D792 Standard Test Method for Density and Specific Gravity(Relative Density) of Plastics by Displacement
  12. ASTM D3171 Standart Test Method for Fiber Content of Resin-Matrix Composites by Matrix Digestion
  13. ASTM E 1269 Standard Test Method for Determining Specific Heat Capacity by Diffrential Scanning Calorimetry
  14. 공업기반 기술개발사업 최종보고서 국립공업기술원
  15. ASTM C177 Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
  16. NASA Contractor Report, NASA CR-896 Thermal and Machanical Properties of a Nondegraded and Thermally Degraded Phenolic-Carbon Composite Engelke, W.T.;Pyron, C.M.Jr.;Pears, C.D.
  17. ADD Report, AD780531
  18. Composites Science and Technology v.29 Thermal Conductivity of Fibre-Phenolic Resin Composites. Part I : Thermal Diffusivity Measurements Mottram, J.T.;Taylor, R.
  19. Composites Science and Technology v.29 Thermal Conductivity of Fibre-Phenolic Resin Composites. Part II : Numerical Evaluation Measurements Mottram, J.T.;Taylor, R.
  20. AIAA/ASME 12th Sturctures, Sturctural Dynamics and Materials Conference Constituent and composite thermal conductivities of phenolic-carbon and phenolic-graphite ablators Clayton, W. A.