论文部分内容阅读
通过观察分析Al-22wt%Si合金在800℃条件下进行过热处理的试验结果,研究了过热处理对Al-22wt%Si合金中初晶硅相的影响,从而得到改善铝硅合金的组织和性能的控制参数和条件。通过分析,发现在900℃下重熔后,在800℃下保温,随着保温时间的延长,初晶硅有明显的生长取向,初晶硅由变异的五瓣星形状生长转变为树枝状生长,树枝状熔断分解后转变为较规则的片状初晶硅,基本观察不到类似铸态共晶组织中存在的五瓣星形状和粗大板片状共晶硅,几乎全部转变为比较细小的短杆状共晶硅,即共晶硅在未变质的状态下出现了经变质处理后的显微特征,得到了改善合金组织和性能的合理控制条件。
The effect of overheating treatment on the primary silicon phase in Al-22wt% Si alloy was studied by observing and analyzing the results of the overheat treatment of Al-22wt% Si alloy at 800 ℃, so as to improve the microstructure and properties of Al-22wt% Si alloy Control parameters and conditions. Through the analysis, it is found that the primary silicon is obviously reorientated at 800 ℃ after remelting at 800 ℃. With the extension of the holding time, the primary silicon has obvious growth orientation. The primary silicon changes from the variant five-star shape growth to the dendritic growth , The dendritic fusions decomposed and transformed into the more regular sheet-like primary silicon. The five-star shape and the coarse plate-like eutectic silicon in the as-cast eutectic structure were basically not observed, and almost all of them were transformed into the relatively small Short rod-shaped eutectic silicon, ie, eutectic silicon in the metamorphic state appeared after the metamorphic microstructure characteristics, obtained to improve the alloy microstructure and properties of the reasonable control conditions.