Formation and microstructure of icosahedral quasicrystals in suction casting Al-6 at.%Mn(-2 at.%Be) alloys have been investigated by scanning electron microscopy, energy-dispersive spectrometer (EDS), x-ray diffraction (XRD), transmission electron microscopy, and differential scanning calorimetry (DSC). Based on the DSC analysis, isothermal annealing was designed, and XRD was performed to analyze the phase composition after heat treatment. The quasicrystalline microstructure of Al-6 at.%Mn(-2 at.%Be) alloys was obtained by suction casting. Be element addition in Al-Mn alloy modified the appearance of the quasicrystalline phases from hexagons to petals; meanwhile, the primary phase transformed from the Al₆Mn compound to quasicrystalline approximant phase. Combined with XRD and scanning results show Be suppressed the formation of Al₆Mn and promoted the formation of a quasicrystalline approximant phase. The thermal stability of the icosahedral phases contributes to a better performance of alloys at higher temperature. EDS analysis shows that the quasicrystalline phase is not a stoichiometric compound but a range of compositions.

中文翻译：

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吸铸Al-6 at。％Mn（-2 at。％Be）合金中二十面体准晶体的组织和热稳定性

通过扫描电子显微镜，能谱仪（EDS），X射线衍射（XRD），透射率研究了吸铸Al-6 at。％Mn（-2 at。％Be）合金中二十面体准晶体的形成和微观结构。电子显微镜和差示扫描量热法（DSC）。基于DSC分析，设计了等温退火，并进行了XRD分析以分析热处理后的相组成。通过抽吸铸造获得了Al-6 at。％Mn（-2 at。％Be）合金的准晶体组织。在Al-Mn合金中添加元素会改变从六边形到花瓣的准晶相的外观；同时，初生相由Al ₆转变Mn化合物为准晶近似相。结合X射线衍射和扫描结果表明，可抑制Al ₆ Mn的形成并促进准晶近似相的形成。二十面体相的热稳定性有助于在更高温度下合金的更好性能。EDS分析表明，准晶相不是化学计量的化合物，而是一系列组成。