温压-原位反应法制备C/C-SiC材料过程中裂纹的形成机制  

Form mechanism of cracks in fabricated process of C/C-SiC frictional composites through warm compacted-in situ reacted process

作　　者：李专[1] 肖鹏[1] 熊翔[1] 杨阳[1] 旷文敏[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2008年第3期506-511,共6页Journal of Central South University:Science and Technology

基　　金：国家"863"计划资助项目(2006AA03Z560);湖南省杰出青年科学基金资助项目(06JJ1007)

摘　　要：以短切炭纤维、石墨粉、硅粉、树脂和粘结剂为原料，采用温压一原位反应法制备C／C-SiC制动材料，研究C／C-SiC制动材料裂纹的形成机制。研究结果表明：树脂炭化裂解产生大量的气体产物，一部分气体产物碰到裂纹壁时受阻凝聚成含C，P，O和H等元素或自由基团的液滴，炭化后液滴转变成直径为2-4μm的高含碳量碳球；另一部分气体产物沿着裂纹试图从试样中排出，当裂纹为封闭状态时便促使微裂纹向前扩展，直至材料开裂；在高温热处理过程中，硅粉熔化后与就近碳源反应生成连续的网络状SiC基体，它对裂纹的扩展有一定的抑制作用，并能愈合试样中的微裂纹。Based on reinforcements of carbon fibers and matrices of carbon and silicon carbide, C/C-SiC composites were fabricated through warm compacted-in situ reacted process. The forming mechanism of cracks during the process of warm compacted-in situ reaction was investigated. The results indicate that the resin emits a series of gas products during carbonization. A part of gas products agglomerate to fluid drops containing C, P, O, H, etc. while blocking at the wall of the crack, and then the drops convert to carbon ball with high carbon content after carbonization, with diameter of 2-4 μm. Other gas products try to release from composites. The gas pushes the tiny cracks to spread when there is no way to release until the crack spreads out of the composites. At the same time, the melted Si reacts with carbon to form continuous SiC matrix shape of network which restrains the spread of cracks or closes up tiny cracks of the composites.

关 键 词：C/C-SIC 温压-原位反应法 裂纹 制动材料 

分 类 号：TB331[一般工业技术—材料科学与工程] TH117.3[机械工程—机械设计及理论]