金刚石混杂碳化硅/铝复合材料的组织与热物理性能

摘要

The thermophysical properties of the SiC/Al composites mixed with diamond (SiC-Dia/Al) were studied through theoretical calculation and experiments. The thermal conductivity and the thermal expansion coefficient of the SiC-Dia/Al were calculated by differential effective medium (DEM) theoretical model and extended Turner model, respectively. The microstructure of the SiC-Dia/Al shows that the combination between SiC particles and Al is close, while that between diamond particles and Al is not close. The experimental results of the thermophysical properties of the SiC-Dia/Al are consistent with the calculated ones. The calculation results show that when the volume ratio of the diamond particles to the SiC particles is 3:7, the thermal conductivity and the thermal expansion coefficient can be improved by 39%and 30%compared to SiC/Al composites, respectively. In other words, by adding a small amount of diamond particles, the thermophysical properties of the composites can be improved effectively, while the cost increases little.%采用理论计算与实验相结合的方法对金刚石混杂SiC/Al复合材料的热物理性能进行研究，采用微分有效介质（DEM）理论和扩展的Turner模型分别计算金刚石混杂SiC/Al复合材料的热导率和热膨胀系数。从金刚石混杂SiC/Al复合材料的微观组织可以看到SiC颗粒与Al之间结合较紧密，金刚石颗粒与Al之间结合不紧密。金刚石混杂 SiC/Al 复合材料的热物理性能的实验结果与理论计算趋势一致。当金刚石颗粒与 SiC 颗粒的体积比为3：7时，混杂SiC/Al复合材料的热导率和热膨胀系数分别提高了39%和30%。因此，当在复合材料中加入少量金刚石颗粒时，其热物理性能得到显著提高，而复合材料的成本略有提高。