Abstract:The vacuum gas pressure infiltration was used to compose the continuous fiber reinforced aluminum matrix composites with unidirectional fiber arrangement using M40 carbon fiber, KD-II SiC fiber and Nextel610 Al₂O₃ fiber as reinforced materials, the matrix alloy was ZL301, the effects of reinforced fiber on interface and mechanical properties of composites were studied. The results show that the reinforcement fiber has a significant effect on the density of the composites, the density of composites which the reinforced fiber is M40 carbon fiber is highest as 99.9%, it has the smallest density, only 2.55 g/cm³, and the fiber arrangement is uniform and the tissue defects are the least. The interfacial reactions of different reinforcing fibers and matrix can occur in varying degrees, showing different degree of fiber damage, the thickness of interface layer and the size of interface phase. The interface layer of Al₂O_3f/Al composite is not found, and the interface layer thicknesses of SiC_f/Al composites and C_f/Al composites are 275.3 nm and 327.4 nm respectively, and short rod like Al₄C₃ phases are found at the interface. The tensile strengths of SiC_f/Al, C_f/Al and Al₂O_3f/Al composites are 780.3 MPa, 670.2 MPa and 587 MPa, respectively. The defect, interfacial reaction degree and fiber damage are the main factors to determine the tensile strength of the composites.

Key words: reinforced fiber; continuous fiber reinforced; aluminum matrix composites; vacuum pressure infiltration; interface; mechanical properties