热解碳界面层与国产T300增韧SiC复合材料拉伸性能关联性初探

Association About the Pyrolytic Carbon and Tensile Properties of T300 Carbon Fiber Reinforced Silicon Carbide Minicomposites

在国产T300碳纤维上沉积不同厚度的热解碳形成界面层，通过前驱体浸渍裂解工艺制备“迷你”Cf／SiC复合材料，考察了T300碳纤维在相同工艺过程中其界面层厚度的最优工艺参数，并研究了热解碳界面层与“迷你”复合材料拉伸性能的关联性。采用SEM与Raman手段对Cf／SiC复合材料进行结构表征。结果表明：该复合材料有明显的裂纹偏转，经高温热处理后界面层状结构更加明显，其复合材料的拉伸强度随热解碳厚度的增加其值有先增加后减小的趋势（PyC的厚度在0～150nm），当界面层厚度约为60nm时达到最大值（1385．7MPa）。

T300 carbon fiber reinforced silicon carbide matrix （C/SiC） minicomposites were prepared by precursor infiltration and pyrolysis, using the different thickness of the pyrolysis carbon on the carbon fiber. The properties of C/SiC composites were tested and compared. The microscopy structure was characterized by SEM and Raman sheet. The results show that the composites have crack deflection, and the layer phenomenon on the composites＇interface is more obvious after the high temperature treatment. Mechanical test results show that the tensile strength of the composites increases as the PyC thickness increases initially and decreases afterwards （ the thickness of with the pyrol- ysis carbon is between 0 to 150 nm）. The maximum tensile strength is 1 385.7 MPa when the pyrolysised carbon thickness is 60 nm.