| Three dimensional network ceramic/metal composite is a new type of composite material.It has been widely concerned for its unique structure and properties.In this paper,the three-dimensional network SiC ceramic was prepared by the method of organic foam impregnation.Its porosity was 80%,and the strength was 3.42MPa,which could be used to prepare composite materials.Then the three-dimensional network SiC ceramic/Al composite was fabricated by in-situ reaction pressureless infiltration method.The effects of powder ratio and infiltration conditions on the preparation of composite were studied.The interface combination and mechanical property of three-dimensional network SiC ceramic/Al composite were studied by different test instruments,like optical microscopy,Vickers hardness tester,XRD diffraction analysis,SEM and pressure experiment machine,etc.The results show that the infiltration depth of Mg is influenced by the incorporation of the material.When Mg amount was less than 5%,the composite material could not be produced.The amount of 8%was the most suitable.The interface reaction can be controlled by the addition of of Si powder,and the formation of Al4C3 was inhibited.The infiltration effect is affected by the infiltration temperature.When the infiltration temperature is lower than 800?,the wettability of metal and ceramic is poor and the composite material can not be obtained.At this temperature,the chemical reaction occurs at the interface between ceramic and metal.Holding time affects the density of the material.When the holding time is less than 2 h,the metal can not infiltrate into the ceramic.With the increase of infiltration temperature,the density of the material is increased.By adjusting the experimental conditions,three-dimensional network SiC ceramic/Al composites with good interface was prepared.Its density reached up to 2.784 g/cm3.and the thermal conductivity was up to 165.38 W/m·K.The compressive strength was 832MPa. |
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