残余Si对C/SiC复合材料力学性能和摩擦学性能的影响  

Effect of Residual Si on Mechanical and Tribological Properties of C/SiC Composites

作　　者：谢建伟 沈益顺 熊杰 刘迪文 陈灵涛 曾磊峰 XIE Jianwei;SHEN Yishun;XIONG Jie;LIU Diwen;CHEN Lingtao;ZENG Leifeng(Hunan Boyun New Materials Co.,Ltd.,Changsha Hunan 410205,China)

机构地区：[1]湖南博云新材料股份有限公司,湖南长沙410205

出　　处：《润滑与密封》2025年第3期180-185,共6页Lubrication Engineering

摘　　要：为研究C/SiC复合材料摩擦引起的高频啸叫机制,以准三维整体针刺碳纤维毡作为预制体,经化学气相沉积法沉积热解碳得到C/C坯体,再经反应熔渗法高温渗硅得到C/SiC复合材料,研究残余Si含量对C/SiC复合材料力学和摩擦学性能的影响,探究残余Si产生啸叫的机制,得出残余的Si的最佳含量。结果表明:残余Si含量对材料的力学性能、摩擦磨损性能以及高频啸叫的产生有重要影响,随着复合材料中残余Si含量的减少,碳化硅含量也减少,碳含量增多,材料的层间结合强度增大,室温热扩散率提高,材料的压缩强度、抗弯强度和剪切强度增大;残余Si在复合材料中碳纤维束和针刺孔隙内聚集成大颗粒硬质点,由于润滑组元不足,大颗粒硬质点在法向压力作用下滑动摩擦,产生模态耦合现象,形成明显的槽状沟槽,产生自激振荡,从而出现摩擦剧烈振动和高频啸叫现象;当复合材料中残余Si的质量分数为5%左右,碳化硅质量分数在40%左右,可得到较稳定的摩擦因数、较低的磨损率和无高频啸叫现象。In order to study the mechanism of high-frequency squeal caused by friction in C/SiC composites,using quasi three-dimensional integral needle punched carbon fiber felt as preform,the C/C body was obtained by chemical vapor deposition method,and then the C/SiC composite was obtained by reaction melt infiltration method.Effect of the residual Si on mechanical and tribological properties of the C/SiC composite was studied.The mechanism of high-frequency squeal caused by residual Si was explored,and the optimal content of residual Si was obtained.The results indicate that the residual Si content has a significant impact on the mechanical properties,friction and wear properties,and the generation of high-frequency squeal of the material.As the residual Si content in the composites decreases,the SiC content decreases and the C content increases,the interlayer bonding strength of the material increases,the room temperature thermal diffusion rate increase,and the compressive strength,bending strength,and shear strength of the material increase.Residual Si accumulates into large particle hard points in carbon fiber bundles and needle punched pores in composite materials.Due to insufficient lubrication components,the large particle hard points slide and rub under normal pressure,causing modal coupling phenomenon,which forms obvious groove like grooves,causes fluctuations in friction force and self-excited oscillation,results in severe friction vibration and high-frequency squeal phenomenon.When the residual Si mass content is around 5%and the silicon carbide mass content is around 40%,a relatively stable friction coefficient,lower wear rate,and no high-frequency squeal composite can be obtained.

关 键 词：C/SIC复合材料 残余硅 摩擦磨损性能 力学性能 啸叫 

分 类 号：TH117.1[机械工程—机械设计及理论] TB332[一般工业技术—材料科学与工程]