电磁铸造2024铝合金组织性能研究

Research on microstructures and mechanical characteristics of EMC and DCC 2024 aluminum alloys

利用电磁铸造技术和普通连续铸造技术铸造了 2 0 2 4变形铝合金 ;采用光学显微镜和扫描电镜分析了其显微组织 ,并对其进行了固溶处理加人工时效 .实验结果表明 ,电磁铸造锭内部组织细小均匀 ,有较高的硬度和良好的疲劳性能 :电磁铸造试样的硬度接近普通连续铸造试样的 2倍 ,疲劳性能约是普通连续铸造试样的 3倍 .电磁铸造试样还有良好的耐磨性 ,磨损量是普通连续铸造试样的一半 .磨损面上浅的犁槽和小的磨损碎片 ,表明电磁铸造试样的磨损机制是磨料磨损和粘着磨损 ;而基体上大量的塑性变形和大块磨损碎片 ,表明普通连续铸造试样的磨损性能较差 。

aluminum alloys made by EMC and DCC were analyzed by optical microscope and scanning electron microscope, solution heat treatment and artificial aging were given to investigate the mechanical properties such as hardness, wear resistance and fatigue. Micrographs show that EMC ingots have fine and uniform grain structure, which make the EMC ingots have high hardness and good fatigue. The hardness of EMC specimens increases one time more than DCC ones and the fatigue is three times as high as DCC ones in as cast state. The EMC specimens also express an excellent characterization in wear resistance; the weight loss is only a half of DCC specimens′. Shallow grooves on worn surface and small wear debris indicate the wear mechanism of EMC ingot is abrasive and adhesive. While the heavy plastic deformation on the matrix and the large block debris shows that the poor wear resistance of DCC ingot is an abrasive delimitation mechanism.