基体合金对连续Al2O3f/Al复合材料微观组织及拉伸强度的影响

Effect of matrix alloy on microstructure and tensile strength of continuous Al2O3f/Al composite

摘要:

选用Nextel610型Al2O3纤维作为增强体，采用真空气压浸渗法制备了纤维体积分数40%、基体合金分别为1A99、ZL210A、ZL301及7075合金的单向连续Al2O3f/Al复合材料，并用NaOH溶液萃取出Al2O3纤维，研究了基体合金对连续Al2O3f/Al复合材料的致密度、纤维损伤及拉伸强度的影响。结果表明：基体合金对连续Al2O3f/Al复合材料的致密度和微观组织有明显影响，其中连续Al2O3f/ZL301复合材料致密度最高为99.2%，组织缺陷最少；连续Al2O3f/1A99复合材料致密度最低为96.8%，这种差异是由于不同基体与纤维之间润湿性不同导致的。不同基体与纤维发生了不同程度的界面反应，最后表现为对纤维的损伤程度不同。连续Al2O3f/1A99、Al2O3f/ZL210A、Al2O3f/ZL301及Al2O3f/7075四种复合材料的拉伸强度分别为465MPa、479MPa、680MPa和389MPa，缺陷、纤维损伤和界面结合强度是影响连续Al2O3f/Al复合材料强度的主要因素。

关键词:基体合金;Al2O3f/Al复合材料;致密度;微观组织;纤维损伤;拉伸强度

Abstract:

The vacuum gas pressure infiltration was performed for the continuous Al2O3f/Al composite with the volume fraction of 40%, of which the reinforced material was Nextel610-Al2O3 fiber, Al2O3 fibers were extracted using NaOH solution, the matrix alloys were 1A99, ZL210A, ZL301 and 7075 alloys, the effects of matrix alloy on the density, fiber damage and tensile strength of continuous Al2O3f/Al composites were studied. The results showed that different matrix alloys have obvious influence on the density and microstructure of the composites. The density of continuous Al2O3f/ZL301 composite is highest as 99.2%, and it has the least defect, the density of continuous Al2O3f/1A99 composite is lowest as 96.8%, the main reason for this difference is the wettability between the matrix and the fiber is different. The degree of interface reaction between different matrix and fiber is different. Eventually, the damage degree of the fiber is different. The tensile strength of continuous Al2O3f/1A99, Al2O3f/ZL210A, Al2O3f/ZL301 and Al2O3f/7075 were 465MPa, 479MPa, 680MPa and 389MPa, respectively. The defect, interfacial reaction degree and the fiber damage are the main factors to determine the tensile strength of the composite.

Key words:matrix alloy; continuous Al2O3f/Al composite; density; microstructure; fiber damage; tensile strength