颗粒增强金属基复合材料的热导率

THE THERMAL CONDUCTIVITY OF PARTICULATE-REINFORCED ALUMINIUM COMPOSITE MATERIALS

本文研究了颗粒增强铝合金(LD_2)复合材料的热导率与颗粒的种类、含量、粒度和在基体中的分布情况之间的关系。制作了不同颗粒含量和粒度的SiCp/LD2和Al_2O_3p/LD_2复合材料试样,用定常热流法测定其热导率。将测试结果与用混合热阻模型推得计算式提供的理论值进行比较,根据测试值和理论值比较的结果,对该计算式提出考虑到颗粒粒度对复合材料热导率影响的修正。得到综合考虑了颗粒的种类、含量、粒度和在基体中均匀分布程度影响的颗粒增强金属基复合材料热导率的理论计算式。

The relation of the effective thermal conductivity of particulato-re-inforced aluminium composite materials with the kind, size, volume fraction and distribution of particles in the composites was investigated in this work.The specimens wore made from alloy (LD2) foil and particulates of SiC with the sizes of 5μm, 10μm, 20μm, and particulates of Al2O3 with the size of 10μm by hot pressing at 580℃. The thermal conductivity of specimens with different volume percentage of particles have been measured by the method of constant heat flow under different temperatures.The measured thermal conductivity of specimens was compared with that calculated from the equation deduced with the aid of a mixed thermo-resistance model.On the basis of comparison an amendment was given to above-mentioned equation, in consideration of the influence of particulate size on thermal conductivity. Thus, a new equation, used in calculating the thermal conductivity of the particulats-reinforced aluminium composite materials, was developed. In this equation the influence of the kind, volume fraction, size of particulates and particulate distribution in matrix on the thermal conductivity of the composites was comprehensively taken into account.