Korean Journal of Materials Research, Vol.11, No.4, 258-265, April, 2001
CFRC 복합재료의 기계적 고온특성
The Mechanical Properties of CFRC under High Temperature
초록
초고온용 내열성 재료인 CFRC(carbon fiber reinforced carbon)에 대하여 고온 하에서 기계적 물성을 측정하기 위하여 특수 제작한 고온로 속에서 2000 ? C 끼지 압축 및 굽힘강도 실험을 수행했다. 시편에 균일한 단축응력이 걸리도록 압축시험용과 4점 굽힘시험용 흑연으로된 치공구를 개발하여 실험했다. 시험결과 CFRC의 온도와 밀도가 증가함에 따라 강도가 증가하는 특성을 거시적으로 설명했으며, 고온하에서 시험기법을 부분적으로 정립했다. 8주자직으로 직조된 CFRC에 일반 강화섬유 복합재료에 적용되는 ASTM의 굽힘시험법에 따라 시편의 L(스판길이)/h(높이) 비를 정하는 것은 부적합함을 확인하고, 인장강도/층간 전단강도의 비에 따라 이 비율을 결정하는 새로운 식과 굽힘에 대한 파손 기준식을 제시했다.
Compression and bending test have been conducted to evaluate the mechanical performance of CFRC at several different temperature up to 2000 ? C . Tools and several grips for the test at high temperature were designed to obtain mechanical properties of CFRP. A major cause of increasing strength according to increasing the density and the temperature were analyzed. SEM method was utilized to find out the damage and the fracture mechanism. The new simple equation for the L(span length)/h(beam height) of specimens and for the failure criterion on the 4 point bending were proposed.
- Liu KC, Brinkman CR, 'Tensile Cyclic Fatigue of Structural Ceramics. In proceedings of the twenty-third automotive technology development contractors', coordination meeting, held at Dearborn, Mi., October 1985. Society of Automotive Engineers, Warrendale, Pa., pp. 279-284, (1986) (1986)
- Hermansson T, Dunlop GL, 'A High-Temperature Tensile Testing Rig for Ceramic Materials, Mechanical Testing of Engineering Ceramics at High Temp.', ELSEVIER APPLIED SCIENCE, pp. 171-176, (1988) (1988)
- McManus HLN, Springer GS, J. Composite Materials., High Temp. Thermo Mechanical Behavior of Carbon-Phenolics and Carbon-Carbon Composites, 26(2), 206 (1992)
- 植村益次, 일본복합재료학회지, FRP의 역학적 특성 시험법의 문제점과 설계 기준(I), 7(1), 32 (1981)
- 宋寬炯外 3人, '複合材料의 機械的 性質 및 破損過程 評價',大韓造船學會誌,25(4), pp.58-68 (1988) (1988)
- Marsh A, Bell DA, 'High-Temperature Flexural Strength of Engineering Ceramics', Mechanical Testing of Engineering Ceramics at High Temp., ELSEVIER APPLIED SCIENCE, pp.177-181, (1988) (1988)
- Zweben C, Smith WS, Wardle M, 'Test Methods for fiber Tensile Strength, Composite Flexural Modulus, and Properties of Fabric-Reinforced Laminates', Composite Materials: Testing and Design; ASTM STP 674, Edited by Tsai SW, ASTM, Phila-delphia, pp. 228-262, (1979) (1979)
- Standard Test Method for Apparent ILSS., ASTM D 2344-84
- Pollock PB, Carbon, Tensile Failure in 2-DC/C Composites, 28(5), 717 (1990)
- Davies IJ, Rawlings RD, Composites, Mechanical Properties in compression of Low Density Carbon/Carbon Composites, 25(3), 229 (1994)