April 2007 High-Load Friction of a C/SiC Hinge Bearing 1145 (4) The grain abrasion is the main wear mechanism of a self- mated C/SiC composite hinge bearing with the testing frame- work. The wear was significantly determined by high load and cyclic mechanical stresses. A smooth and compact tribo-layer was formed. and the wear debris that remained in the wear track 3.5 kN led to several shallow cracks on the contact surfac 9to was ground to a very fine powder. The shallow grooves alor the sliding direction were mainly caused by the relative move- ment of contact asperities. Load increased to a level above References H G. Wulz and U. Trabandt, "Large Integral Hot CMC Structures De rs". AIAA-97-2485. Amencan Institute of "R. Kladtke, N. Puttmann, and E. D. Graf, ""X-38 European Partnership AlAA 1999-99-4936, The American Institute of Aeronautics and Astronautics, 10 um Development of Hot CMC Structures for Space Re- xperiments": International Air and Space Symposium Fig. 11. Contact surfaces of carbon fiber reinforced silicon carbide atrix(CSiC) after friction against a CSiC ring under a load of +A Muhlratzer and H. Pfeiffer, "CMC Body Flaps for The X-38 Experimental 3.5 kN and a constant sliding velocity of 33 x 10- m/s Space Vehicle. " Ceran. Eng. Sci. Pro, ABI/INFORM Trade Industry, 23 [31 331-8(2002) rtel, H. Weihs, I. Fischer, and M. Dogigli, "Thermal-Mechanical Q fication Tests of Complex CMC Re-Entry Structures, "Ceram. Eng. Sci. Pro. IV. Conclusions ABI/INFORM Trade Industry, 24 (4)281-1(2003). oue to Tribological Prob- g with required good mechanical prop- NO1 Annual Meeting, Society of Tribologists and Lubrication Engineers, made of 2D-C/Sic composites by CVI. The damaged showed non-brittle failure behavior resulting from the Renz, C/C-SiC Composites for Ad- of a single fiber and fiber cluster. The flexural strength vanced Friction Systems, Adv. Eng. Mater. 4. 427-36(2002). Z S. Pak,"Ct SiC/C Composites for Tribological Application, Key Eng compressive strength were 450 MP and 360 MPa, respectively. Purdy. T. Walker, and S Horst. C/SiC Material Evalu- ( 2) The CVI process offered a potential method to manu- ation or aircraft brake Application. " Key Eug. ater 164-165 802(1999 facture the C/SiC composite hinge bearing of a stable and reli- arbon Silicon Carbide Composite, " Cam. Sci. Tech, 61 [3]417-23 able friction property under a high load. With a material density f 2.03 g/cm, a constant friction coefficient was obtained as 0.68 on increasing the load up to 5800 N. 1153-60002) ( The hinge bearing based on C/SiC composites demon C -D. Um and S.-S. Kim. ""Wear and Wear Transition rated good wear resistance and load-carrying ability due to the T.E. Fischer. Z. Zhu. H. Kim, and D. S. Shin, "Genesis and Role of Wear w wear and the small deformation under high loads. T e wear Vear of Ceramics, Wear, 245 53-60(2000) ate of the C/SiC composites was only 1/10-1/20 of that of the M. Hsu. "Wear and Wear Transition Mechanisms of cer- Ti alloy, and the deformation was only 1/10 of that caused by [-2]112-2(1996) ues-Carmes. " Wear Mechanism of silicon the Ti alloy Carbide: New Observations, " Wear, 174 [1-21239-42(1994)IV. Conclusions (1) The hinge bearing with required good mechanical prop￾erties was made of 2D-C/SiC composites by CVI. The damaged specimen showed non-brittle failure behavior resulting from the pull-out of a single fiber and fiber cluster. The flexural strength and the compressive strength were 450 MP and 360 MPa, respectively. (2) The CVI process offered a potential method to manu￾facture the C/SiC composite hinge bearing of a stable and reli￾able friction property under a high load. With a material density of 2.03 g/cm3 , a constant friction coefficient was obtained as 0.68 on increasing the load up to 5800 N. (3) The hinge bearing based on C/SiC composites demon￾strated good wear resistance and load-carrying ability due to the low wear and the small deformation under high loads. The wear rate of the C/SiC composites was only 1/10–1/20 of that of the Ti alloy, and the deformation was only 1/10 of that caused by the Ti alloy. (4) The grain abrasion is the main wear mechanism of a self￾mated C/SiC composite hinge bearing with the testing frame￾work. The wear was significantly determined by high load and cyclic mechanical stresses. A smooth and compact tribo-layer was formed, and the wear debris that remained in the wear track was ground to a very fine powder. The shallow grooves along the sliding direction were mainly caused by the relative move￾ment of contact asperities. Load increased to a level above 3.5 kN led to several shallow cracks on the contact surface. References 1 H. G. Wulz and U. Trabandt, ‘‘Large Integral Hot CMC Structures Designed for Future Reusable Launchers’’; AIAA-97-2485, American Institute of Aero￾nautics and Astronautics, 1997. 2 R. Kladtke, N. Puttmann, and E. D. Graf, ‘‘X-38 European Partnership’’; AIAA 1999-99-4936, The American Institute of Aeronautics and Astronautics, 1999. 3 H. Hald and H. Weihs, ‘‘Development of Hot CMC Structures for Space Re￾entry Vehicles Via Flight Experiments’’; International Air and Space Symposium and Exposition, AIAA 2003-2696, 2003. 4 A. Muhlratzer and H. Pfeiffer, ‘‘CMC Body Flaps for The X-38 Experimental Space Vehicle,’’ Ceram. Eng. Sci. Pro., ABI/INFORM Trade & Industry, 23 [3] 331–8 (2002). 5 M. Ortelt, H. Weihs, I. Fischer, and M. Dogigli, ‘‘Thermal–Mechanical Quali- fication Tests of Complex CMC Re-Entry Structures,’’ Ceram. Eng. Sci. Pro., ABI/INFORM Trade & Industry, 24 [4] 281–7 (2003). 6 Robert L. Fusaro, ‘‘Preventing Spacecraft Failures Due to Tribological Prob￾lem’’; 2001 Annual Meeting, Society of Tribologists and Lubrication Engineers, NASA/TM—2001-210806, Orlando, FL, 20–24, 2001. 7 W. Krenkel, B. Heidenreich, and R. Renz, ‘‘C/C–SiC Composites for Ad￾vanced Friction Systems,’’ Adv. Eng. Mater., 4, 427–36 (2002). 8 Z. S. Pak, ‘‘Cf/SiC/C Composites for Tribological Application,’’ Key Eng. Mater., 164–165, 820–5 (1999). 9 S. Vaidyaraman, M. Purdy, T. Walker, and S. Horst, ‘‘C/SiC Material Evalu￾ation for Aircraft Brake Application,’’ Key Eng. Mater., 164–165, 802–8 (1999). 10J.-Y. Paris, L. Vincent, and J. Denape, ‘‘High-Speed Tribological Behavior of a Carbon/Silicon Carbide Composite,’’ Com. Sci. Tech., 61 [3] 417–23 (2001). 11B. Venkataraman and G. Sundararajan, ‘‘The Influence of Sample Geometry on the Friction Behaviour of Carbon–Carbon Composites,’’ Acta Mater., 50, 1153–6 (2002). 12S.-J. Cho, C.-D. Um, and S.-S. Kim, ‘‘Wear and Wear Transition Mechanism in Silicon Carbide During Sliding,’’ J. Am. Ceram. Soc., 78 [4] 1076–8 (1995). 13T. E. Fischer, Z. Zhu, H. Kim, and D. S. Shin, ‘‘Genesis and Role of Wear Debris in Sliding Wear of Ceramics,’’ Wear, 245, 53–60 (2000). 14Y. Wang and S. M. Hsu, ‘‘Wear and Wear Transition Mechanisms of Cer￾amics,’’ Wear, 195 [1–2] 112–2 (1996). 15J. Takadoum, Z. Zsiga, and C. Roques-Carmes, ‘‘Wear Mechanism of Silicon Carbide: New Observations,’’ Wear, 174 [1–2] 239–42 (1994). & Fig. 11. Contact surfaces of carbon fiber reinforced silicon carbide matrix (C/SiC) after friction against a C/SiC ring under a load of 3.5 kN and a constant sliding velocity of 33 10
3 m/s. April 2007 High-Load Friction of a C/SiC Hinge Bearing 1145