(中南大學 材料科學與工程學院，長沙 410083)
摘 要: 采用分形方法探討70%Si-Al熱沉材料的典型熱性能與顯微組織之間的關(guān)系，針對不同Si相尺寸的分形特征進行描述。結(jié)果表明：70%Si-Al合金的顯微組織具有自相似的界面形態(tài)和典型的分形特征，使用分形維數(shù)能夠直觀表示出70%Si-Al合金中兩相間的界面性質(zhì)；計盒維數(shù)法和質(zhì)量維數(shù)法2種不同的分形描述方法反映的規(guī)律相同；Si相平均尺寸為75 μm的試樣比Si相平均尺寸為45 μm的試樣的分形維數(shù)更小；隨著溫度的升高，分形維數(shù)較小的合金熱導率較大，熱膨脹系數(shù)增加的幅度卻減小。
關(guān)鍵字: 70%Si-Al合金；分形維數(shù)；顯微組織；熱性能
（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
