摘要
The AlSi20/8009 aluminum alloy was heated to high temperatures near the melting point and cooled to investigate the effect of external Si addition on the phase evolution of Al12(Fe,V)3 Si dispersion. Differential scanning calorimeter, scanning electron microscope, energy dispersive spectrometer and X-ray diffractometer were employed.The results showed that Al12(Fe,V)3 Si and Si phases evolved into a needle-like Al4.5 Fe Si phase and a nano-sized V-rich phase during holding the alloy at 580-600℃. With increasing holding temperature to 620-640℃, Al4.5 Fe Si and nano-sized V-rich phases evolved reversibly into Al12(Fe,V)3 Si and Si phases, of which Al12(Fe,V)3 Si occupied a coarse and hexagonal morphology. During the alloy(after holding at 640 ℃) furnace cooling to 570 ℃ or lower, Si and Al12(Fe,V)3 Si phases evolved into strip-like Al4.5 Fe Si and the V-rich phases, which is a novel formation route for Al4.5 Fe Si phase different from Al-Fe-Si ternary system.
将AlSi20/8009铝合金加热至熔点附近温度后进行冷却,利用差热扫描量热仪、扫描电子显微镜、能量分散谱仪和X射线衍射仪研究外加Si对Al12(Fe,V)3Si弥散体相演变的影响。结果发现,当AlSi20/8009铝合金在580~600℃保温时,Al12(Fe,V)3Si和Si相演变成为针状Al4.5Fe Si相和富V纳米相。提高保温温度至620~640℃,Al4.5Fe Si相和纳米相逆向演变为Al12(Fe,V)3Si相和Si相,其中Al12(Fe,V)3Si相具有粗大六边形形貌。当AlSi20/8009铝合金在640℃保温后冷却至570℃或更低的温度时,Si相和粗大六边形Al12(Fe,V)3Si相演变成片状Al4.5Fe Si相和富V纳米相,这是一种不同于Al-Fe-Si三元体系的Al4.5FeSi相的新型形成路径。
基金
Project(CX20190310)supported by the Hunan Provincial Innovation Foundation for Postgraduate,China
Project(51574118)supported by the National Natural Science Foundation of China
Project(2016GK4056)supported by Key Technologies R&D in Strategic Emerging Industries and Transformation in High-tech Achievements Program of Hunan Province,China
Project(2018GK5068)supported by Innovation and Entrepreneurship Technology Investment Project of Hunan Province,China。
