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采用挤压铸造方法制备mullite/Al 4.0Cu 1.85Mg铝基复合材料 ,用硬度测试 (HB)、差示扫描量热仪(DSC)和分析透射电镜 (ATEM)等手段 ,研究了复合材料及其基体合金的时效硬化特性、时效相的析出序列、析出相和位错的微观形貌特征以及界面结构。结果表明 :mullite纤维的引入抑制了GPB区的形成 ,提高了基体合金的时效硬度 ,但纤维加速复合材料时效硬化的作用不明显。这是由于Mg元素在纤维 /基体界面处发生了界面反应 ,生成镁铝尖晶石 (MgAl2 O4 ) ,使复合材料中非纤维区内实际Mg含量降低所致。
The mullite / Al 4.0Cu 1.85Mg aluminum matrix composites were prepared by extrusion casting method. The hardness of the composite was measured by hardness test (HB), differential scanning calorimeter (DSC) and transmission electron microscope (ATEM) The age hardening properties of the matrix alloy, the precipitation sequence of the aging phase, the micro-morphological features of precipitated phase and dislocation and the interface structure. The results show that the introduction of mullite fibers inhibits the formation of GPB region and improves the aging hardness of the matrix alloy. However, the role of fiber accelerated composites aging hardening is not obvious. This is due to the interfacial reaction of the Mg element at the fiber / matrix interface, resulting in the formation of MgAl 2 O 4, resulting in a reduction of the actual Mg content in the non-fiber zone of the composite.