增密工艺对C/C-Cu复合材料组织和性能的影响

Influence of Densification Process on Microstructure and Properties of C/C-Cu Composite

为了探究增密工艺对C/C-Cu复合材料组织和性能的影响,分别采用化学气相渗透(CVI)和先驱体浸渍裂解转化(PIP)对2.5D针刺碳毡进行增密处理,得到由热解碳和树脂碳填充的C/C增强体,采用真空浸渗工艺制备了C/C-Cu复合材料,并对其进行了组织分析和性能测试。结果表明:采用CVI增密制备的C/C-Cu复合材料中TiC界面层更薄,热解碳对碳纤维起到了较好的保护作用,垂直、平行方向的电阻率分别为0.72、0.63μΩ·m、压缩强度分别为367.61、326.87 MPa,抗拉强度为62.54 MPa,其导电性能、压缩强度、抗拉强度以及塑性均优于PIP增密,破坏机制为纤维拔出破坏;采用CVI增密制备的C/C-Cu复合材料硬度值为77.28 HBW,略低于PIP增密(81.59 HBW),但二者差异较小。综上,CVI增密工艺更适合用来制备C/C-Cu复合材料的C/C增强体。

In order to explore the effect of densification process on the microstructure and properties of C/C-Cu composite,the 2.5D needle-punched carbon felt was densified by chemical vapor infiltration(CVI) and precursor impregnation pyrolysis(PIP) to obtain C/C reinforcements filled with pyrolytic carbon and resin carbon,respectively.C/C-Cu composite was prepared by vacuum infiltration process,and the microstructure analysis and performance test were carried out.The results showed that the TiC interface layer in the C/C-Cu composite prepared by CVI process was thinner,and the pyrolytic carbon had a better protection effect on the carbon fiber.The resistivity and compressive strength in the vertical(parallel) direction were 0.72(0.63)μΩ·m,367.61(326.87)MPa,respectively.And the tensile strength is 62.54 MPa.Its electrical conductivity,compressive strength,tensile strength,and plasticity were better than those of PIP process.The failure mechanism was fiber pull-out failure.The hardness value of C/C-Cu composite prepared by CVI process was 77.28 HBW,which was slightly lower than that of PIP process(81.59 HBW),but the difference between them was small.In conclusion,the CVI densification process was more suitable for the preparation of C/C reinforcements of C/C-Cu composites.