Simulation And Experimental Research On Thermal Conductivity Of SiC_p/Al Composite With Pore And Inter-phase

The effect of two microstructures, including pore and inter-phase on the thermalconductivity of SiCp/Al composite was investigated in this paper. In the aspect of pore:the effect of porosity, poro diameter and pore shape on the thermal conductivity ofcomposite was discussed and analyzed by simulation and experiment. In the aspect ofinter-phase: the effect of the type, thickness and cover ratio of inter-phase on thethermal conductivity of composite was discussed and analyzed by simulation.Pore is an important factor to lower the thermal conductivity of SiCp/Al composite:the thermal conductivity of composite decreases with increasing of porosity, decreasingspeed gradually slow down. The samples preparation by natural accumulation of powder,porosity range of0.7%to7.8%, the thermal conductivity from160.9W·m-1·k-1significantly decreased to118.8W·m-1·k-1; the samples preparation by preform,porosity range of2.8%to9.4%,the thermal conductivity from144.7W·m-1·k-1significantly decreased to112.9W·m-1·k-1; under the same porosity, thermalconductivity of the sample with larger average pore diameter is slightly larger than thesample with smaller average pore diameter, thermal conductivity of the sample withregular shaped pores is slightly larger than the sample with irregularly shaped pores.The effect of inter-phase on the thermal conductivity of SiCp/Al composite wasdetermined by the thermal conductivity of inter-phase：（1）Under the particle wascompletely covered by inter-phase, the thermal conductivity of composite increaseswith increasing of thermal conductivity of inter-phase, increasing speed gradually slowdown. Thermal conductivity of composite have a significant decline when the thermalconductivity of inter-phase was in the range1.4W·m-1·k-1to90W·m-1·k-1; thermalconductivity of composite have no significant change when the thermal conductivity ofinter-phase was in the range90W·m-1·k-1to180W·m-1·k-1; thermal conductivity ofcomposite have a slight rise when the thermal conductivity of inter-phase was more than180W·m-1·k-1.Thermal conductivity of composite decreases from123.92W·m-1·k-1to67.82W·m-1·k-1with the thickness of SiO2increases from0.5μm to4.5μm; thermalconductivity of composite decreases from161.96W·m-1·k-1to155.68W·m-1·k-1withthe thickness of Ni increases from0.5μm to4.5μm; thermal conductivity of compositeincreases from167.6W·m-1·k-1to172.32W·m-1·k-1with the thickness of Cu increasesfrom0.5μm to4.5μm.（2）Under the particle was not completely covered by inter-phase, the effect of inter-phase on the thermal conductivity of SiCp/Al compositewas weaken. Thermal conductivity of composite from159.3W·m-1·k-1decreased to148.48W·m-1·k-1with the coverage ratio of2μm SiO2from25%increased to83.3%;thermal conductivity of composite from161.77W·m-1·k-1dereased to159.63W·m-1·k-1with the coverage ratio of2μm Ni from25%increased to83.3%; thermal conductivityof composite from163.9W·m-1·k-1increases to167.44W·m-1·k-1with the coverageratio of2μm Cu from25%increased to83.3%.