Study On Preparation Of High Volume Fraction SiC_p/6061Al Composites By Vacuum Electrothermal Extruding Sinter

High volume fraction of SiC_p/Al composite materials,due to its superior mechanical properties and thermal physical properties such as high heat conductivity,low thermal and expansion coefficient,have been widely applied to various fields from military aerospace to the civilian market,such as high power civil electronic,IGBT(insulated gate bipolar transistor)power base board,wireless base stations,automotive electronics,high brightness LED(light emitting diode),etc.,which is one of the hottest composite materials at present.Traditional preparation methods have some shortcomings,which limits the production of composite materials.Nowadays there are many studies about the SiC_p/Al composite materials fabrication,but there are few reports about the properties of SiC_p/Al composite materials related to the distribution uniformity.This paper describes the preparation of 60% SiC_p/6061 Al composites using vacuum electric heat extrusion sintering preparation on the understanding that two different compression methods were used for continuous compression and point compression.The thermal physical properties,mechanical properties,density,hardness test and microstructure analysis are investigated and the performance of SiC_p/6061 Al composites in radial direction and axial direction are studied,the results show that:(1)The SiC_p/6061 Al composite material prepared by the electric heat extrusion sintering vacuum forming technology has good formability and smooth surface.Microstructure shows that the enhance body of the SiC particles are uniform distribution and compact organization;(2)The thermal conductivity of the center is higher than the edge in the radial direction.In the axial direction,area contacted with dynamic graphite indenter has a relatively higher thermal conductivity,compared with those contacted with hydrostatic indenter.The thermal expansion coefficient is higher in the center area;(3)Flexural strength in the radial direction change rule for the flexural strength is higher than at the edge of the area near the center of flexural strength,the density and hardness change in radial direction is consistent with the change rule of flexural strength;(4)under the condition of the point compression,SiC_p/6061 Al various properties of composites are improved,and the change rule in the radial direction and axial direction is consistent with the continuous compression.