高含量Si_P/A l热控制复合材料性能研究

Study on property of high content Si_P/Al thermal management composite materials

首次采用无压浸渗工艺,使A l液自发浸渗进入多孔S i预制件中,制备出A l/70vol%S iP复合材料,对该材料的浸渗过程、组织特点和热物理性能进行了分析.研究发现,与其他方法相比,无压浸渗料获得的高含量S iP/A l复合材料,在性能上具有低密度、高导热率、低膨胀系数等特点,具备了热控制材料的基本特征,明显优于Cu-W、Fe-N i合金、Kovar合金、S iCp/A l复合材料,以及采用其他工艺制备的S i/A l复合材料.

High content Sip/Al composite is a new kind of thermal management materials. Someone adopted Osprey or Squeeze infiltration methods to prepare the material. Sip/Al composites were fabricated successfully by pressureless infiltration method for the first time in the paper. Al liquid infiltrate spontaneously into porous Si perform under N2 atmosphere. It will be solidified subsequently under controlling to make a bulk composite. Furthermore, the process of infiltration, structure characteristics, and thermal physics properties were analyzed in the paper. We found that the high content Sip/Al composite obtained by pressureless infiltration method is very different than Sip/Al composites obtained by other methods. It have some particularly properties. The results show that of high volume content Si/Al composites is characterized by lower density （2.3 - 2.5 g/cm^3 ） , high thermal conductivity（94.8 - 128.7 W/（ m · K） ）, lower expand coefficient, （ （5. 1 -7.8） × 10^-6/K （50- 100 ℃ ）） etc, and indicate that it has the basic characteristic of thermal management material. Contemporary, compared with other thermal management materials, the new material obviously excels as Cu - W, Fe- Ni alloy, Kovar alloy, SiCp/Al composites and Si/Al composites fabricated by other process in thermal physics property.