(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用分形方法探讨70%Si-Al热沉材料的典型热性能与显微组织之间的关系，针对不同Si相尺寸的分形特征进行描述。结果表明：70%Si-Al合金的显微组织具有自相似的界面形态和典型的分形特征，使用分形维数能够直观表示出70%Si-Al合金中两相间的界面性质；计盒维数法和质量维数法2种不同的分形描述方法反映的规律相同；Si相平均尺寸为75 μm的试样比Si相平均尺寸为45 μm的试样的分形维数更小；随着温度的升高，分形维数较小的合金热导率较大，热膨胀系数增加的幅度却减小。
关键字: 70%Si-Al合金；分形维数；显微组织；热性能
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The fractal description was applied to 70%Si-Al alloy to analyze the relationships between the thermal properties and the microstructures. The fractal character of different sizes of Si phase was researched. The results show that the microstructures of 70%Si-Al reveal a self-similar irregular interface structure and possess typical fractal character. Both the calculated box-counting fractal dimension and mass fractal dimension acquire the similar behaviors. The fractal dimension values of the microstructures decrease when the Si size changes from 45 μm to 75 μm. And the thermal conductivity of 70%Si-Al alloy increases but the coefficient of thermal expansion changes slightly with decreasing fractal dimension values.
Key words: 70% Si-Al alloy; fractal dimension; microstructures; thermal properties
