C_F／Al复合材料界面质量控制研究

采用挤压铸造工艺参数最优化、纤维表面涂层等手段，研究ＣＦ／Ａｌ复合材料界面质量控制和提高复合材料强度的效果．碳纤维和涂覆ＳｉＣ的碳纤维增强Ａｌ－１０Ｓｉ复合材料的挤压铸造最佳温度分别为Ｔｆ＝７３３Ｋ，Ｔｍ＝１０３３Ｋ和Ｔｆ＝７５３Ｋ，Ｔｍ＝１０５３Ｋ．不同的涂层对界面质量有不同的影响，那些阻止界面反应、调节界面结合状态的涂层增强效果较好，如ＰＣＳ－ＳｉＣ可使复合体系强度提高８９％；Ｋ２ＺｒＦ６也有改善界面质量的功能，但加入量过大，导致复合材料强度的下降．随界面剪切强度的增大，复合材料强度增加．结果表明高模量碳纤维所允许的最佳界面剪切强度（τ０），远远大于低模量碳纤维所允许的τ０．从而具有较好的增强效果．

BETTERMENT ON INTERFACE OF C_F/Al COMPOSITES

An approach to better the interface of the CF/Al composites was carried out on the optimization of the technological parameters for coating of the C fibres and in squeeze casting process. The optimized temperatures of preform, Tf, for bare or PCS SiC-coated C fibres and of molten metal, Tm, Al-10Si matrix seem to be matched by 733 K and 1033 K or 753 K and 1053 K respectively. The quality of interface in composites is different from the coating of C fibres. Such coating, either to retard the interfacial reaction or to better the bonding state, may improve the strength of composites, e.g., increase of strength of a composite up to 89% by PCS SiC-coating and also improvement of wettability by K2ZrF6 solution. The strength of composites increases with the increase of the interfacial shear stress. Furthermore,the optimized shear stress of M40/Al composites with high modulus C fibers is higher than that of the CF/Al composites with low modulus fibers, thus the higher tensile strength was obtained.