热解炭结构对C/C复合材料摩擦磨损性能的影响

以炭纤维整体毡为预制体,采用热梯度化学气相渗透(CVI)工艺制备了2种不同结构基体炭的C/C复合材料,即粗糙层结构材料与光滑层结构材料。研究了2种不同结构基体炭的C/C复合材料在沉积态和热处理态的显微结构、热物理性能及摩擦磨损性能。研究结果表明,在沉积态,2种结构材料都产生严重的氧化磨损,提高材料的石墨化度可显著降低材料的氧化磨损;不管是在沉积态还是在热处理态,RL结构材料的刹车性能曲线都明显优于SL结构材料的刹车性能曲线,这表明热解炭的微观结构不同是造成C/C复合材料摩擦性能差异的根本原因。

Influence of the microstructure of pyrocarbon on friction and wear properties of C/C composites

With the carbon fiber integrated felts used as preforms, two different types of carbon-carbon(C/C) composites, namely, rough laminar (RL) structure materials and smooth laminar (SL) structure materials were fabricated by thermal gradient CVI process. The microstructure and thermal physical properties of the materials in different conditions were investigated by means of microscopy, X-ray diffraction, hardness tester, thermal conductivity tester respectively. Furthermore, the frictional and wear properties of the materials were also investigated. The results show that the effects of microstructure of pyrocarbon on the frictional properties outweigh by far the effects of bulk density on the corresponding properties when the bulk density amounts to a certain degree, both in as-deposited and in heat-treated condition, the frictional properties of RL structure material is obviously superior to the SL structure materials, which implies that the decisive factor in determining the frictional behavior of C/C composites turns to be the microstructure of pyrocarbon.