结构炭/炭复合材料力学性能及微观结构研究

采用四向编织、快速化学气相渗透致密化新工艺制备了炭／炭复合材料，其弯曲强度达３２０ＭＰａ。分析研究了这种材料的力学性能特征。利用ＳＥＭ和高分辨ＴＥＭ分析了基体炭、炭纤维／基体灰界面的精细结构，发现炭纤维呈单根被基体炭包围，基体现灰呈层片状，为二维有序的乱层石墨结构；在炭纤维与基体炭之间存在着过渡相，这一过渡相厚度的约几十纳米，随着与炭纤维之间距离的增大，它们之间形成的夹角由小变大，这一过渡相即为炭

A STUDY OF MECHANICAL PROPERTIES AND MICROSTRUCTURE FOR STRUCTURAL CARBON/CARBON COMPOSITES

The super high temperature structural carbon/carbon composites (C/C) with the flexural strength of 320 MPa was weaved by 4D method and densified by new technology of rapid chemical vapor infiltration. The characteristics of mechanical properties for structural C/C was analyzed. The microstructure of CVI carbon and interface between carbon fiber and CVI carbon was studied using SEM and HRTEM. The results show that single carbon fiber is surrounded by CVI carbon, and CVI carbon is of disorderly layered microstructure that is in perfect order in 2D plane. There is transitional phase whose thickness is close to tens nm between carbon fiber and CVD carbon. The phase is basically paralled to the carbon fiber surface, and the angle is increased as the distance to carbon fiber is raised. The transitional phase is the interface between carbon fiber and CVI carbon.