| Vacuum gas pressure infiltration was performed for the continuous Si Cf/Al composite with the volume fraction of 40%, of which the reinforced material was Si C fiber fabricated by precursor method, the matrix alloys were ZL102, ZL114 A,ZL205A and ZL301 alloy, study on the effects of matrix alloy on microstructure and mechanical properties of continuous Si Cf/Al composites, and explore the effects of different matrix alloy on interface structure, fiber damage and fracture behavior. The main conclusions are as follows:It has a significant impact that matrix alloy on the density of the composite material.Which the density of Si Cf/ZL102, Si Cf/ZL114 A and Si Cf/ZL205 A is respectively 97.30%,97.58% and 97.70%, little difference, Si Cf/ZL301 composite material has the highest density,to 99.08%, Si Cf/ZL301`s density of the bottom infiltration is higher than the upper infiltration, which is impregnated preform gas is compressed to liquid aluminum upper preform due; the density of the composite material which is also one of the lowest,only2.53g/cm3Alloy matrix organization under vacuum pressure impregnation prepared conditions is conventional cast under pressure solidification, matrix alloy has a significant impact on the SEM microstructure of the composite. Among them, Si Cf/ZL102, Si Cf/ZL114 A and Si Cf/ZL301 three kinds of composite,fiber dispersion, fiber and matrix combination of good,there is fiber and fiber bonding and impregnating porous about organization of Si Cf/ZL205 A composite. Uniformity of fiber dispersion with substrate wetting between the matrix alloy and fiber and aluminum alloy liquid flow have a direct link.TEM analysis revealed that the matrix alloy has a significant impact on the interfacial structure of composite materials. Si Cf/ZL102 composite material is not apparent that the interface layer, Si C fibers are rough edges, and the distribution of debris-like substance,found at the interface of tiny needle-like Al4C3 phase; Si Cf/ZL114 A composite material can be seen about89.84 nm thick interface layer, the color depth than the Si C fibers and consistent color, found by the edge of the fiber matrix Al4C3 growth phase; interface layer thickness of Si Cf/ZL205 A composite is about 273.3nm, interface block Al4C3 and Si C fibers form a "bridge" phenomenon;Si Cf/ZL301 composite there are also obvious interface layer and the interfacial layer thickness of about 286.80 nm,phase complex, the presence of amorphous Si and may contain Mg Al2O3.Si,Mg,Cu elements that alloy matrix contained for fiber enrichment capabilities and the ability to inhibit the effects of interfacial reaction composite Have a significant impact on interface structure.Tensile strength of the matrix alloy is unlikely to affect the tensile strength of the composites,no significant influence of. The study found composite mechanical properties of different matrix alloy vary greatly,Average tensile strength of composite that matrix alloy is ZL102, ZL114 A,ZL205A and ZL301 are: 615.7MPa, 475.9MPa, 385.1MPa and 769.3MPa.Extracted Si Cf/ZL102, Si Cf/ZL114 A, Si Cf/ZL205 A and Si Cf/ZL301 composite with Na OH solution, average tensile strength of Si C fibers were 50.94%, 41.51%, 25.09% and 76.93% of raw silk, shows that the tensile strength of the composites and tensile strength of Si C fibers after extraction have the same variation.Comparative analysis of four different matrix alloy composite`s fracture surface showed:Si Cf/ZL102 composites have more fiber pull-out fracture, its interface bonding is not strong;Si Cf/ZL205 A composite materials, the fracture flush, interfacial reaction is serious, more brittle phase interface; Si Cf/ZL301 composite materials, the fracture fiber pull less, but the fracture showed uneven, interface combined with moderate; Si Cf/ZL114 A fracture extent varies weak interfacial bonding slightly stronger. |
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