孔隙率对SiC_p/Al复合材料热导率影响

Effect of porosity on thermal conductivity of SiC_p/Al composites

通过无压渗透方法制得不同孔隙率SiCp/Al复合材料,采用了有限元数值模拟方法并与实验相结合研究了孔隙率对复合材料热导率的影响,并与MEMA模型计算值进行了对比。结果表明：通过改变无压浸渗温度和时间,可以制备出2.8%-9.4%范围内可调的含孔隙复合材料;在有限元数值模拟中,当孔隙率为小于6%时,热导率下降较快,反之,下降平缓。含孔隙复合材料有限元数值模拟值和实验结果较吻合,有一定的参考价值。随着孔隙率的增大,MEMA模型计算值和有限元模拟值的偏差越大。

SiCp/ Al composite materials with different porosity were prepared by pressureless infiltration process. The effects of porosity on thermal conductivity of the composites were examined by finite element method and experimental measurement,and the results were compared with calculatiaon values by MEMA model. The results indicate that the composite materials containing 2. 8%-9. 4% porosity can be prepared by changing the pressureless infiltration temperature and time. Finite element numerical simulation shows that the thermal conductivity of the composites decreases rapidly with increasing porosity to 6% and then the decreasing slows down for further increasing the porosity. The thermal conductivity by finite element numerical simulation is in agreement with the experimental results. With the increase of porosity,larger deviation between the calculation values by MEMA model and finite element simulation values is observed for the thermal conductivity.