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本文通过金相显微镜和透射电镜观察了急冷 Al_(1-x)Si_x(x=1-25wt-%)合金的微观结构。结果表明:急冷使晶粒大大细化,结构均匀,而且彻底改变了初生 Si 相的形貌和分布。急冷引入了高密度缺陷,这些缺陷以空位、位错和位错环等形式存在。而急冷样品中 Si 的析出可能是由于过剩空位起了促进作用。通过 X 光衍射,分析了富 Al 相的晶格常数与成分的关系,认为高 Si 含量合金中富 Al 相的反常晶格常数可能是内应力引起的。
In this paper, the microstructure of the rapidly quenched Al_ (1-x) Si_x (x = 1-25wt-%) alloy was observed by optical microscope and transmission electron microscope. The results show that the quenching makes the grain refinement and uniform structure, and completely changes the morphology and distribution of primary Si phase. Quenching introduces high-density defects that exist in the form of vacancies, dislocations and dislocation loops. However, the precipitation of Si in the quenched samples may be due to the excess vacancy. The relationship between the lattice constants and composition of the Al-rich phase was analyzed by X-ray diffraction. It is considered that the anomalous lattice constant of the Al-rich phase in the high Si alloy may be caused by the internal stress.