Preparation of semi-solid 6061 aluminum alloy slurry by serpentine channel pouring  

采用蛇形通道浇注法制备半固态6061铝合金浆料

作　　者：Nai-yong LI Wei-min MAO Xiao-xin GENG 李乃拥;毛卫民;耿晓鑫(北京科技大学材料科学与工程学院,北京100083)

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第3期739-749,共11页中国有色金属学报（英文版）

摘　　要：The semi-solid 6061 aluminum alloy slurry was prepared by a serpentine channel pouring process. The effects of pouring temperature, bend number and bend diameter on the microstructures were investigated. Microstructural evolution mechanism of the semi-solid slurry during the pouring process was also analyzed. The results show that the grain is refined and the grain roundness is improved by controlling the pouring temperature close to the liquidus temperature, and the nucleation rate of primary α(Al) grains is effectively increased via increasing the bend number and decreasing the bend diameter. The primary grains are not only formed directly from the alloy melt via chilling nucleation and heterogeneous nucleation, but also evolved from the fractured dendrite fragments. Meanwhile, the heat exchange between the melt and the serpentine channel is increased by the “self-stirring” effect in the melt, which also promotes the refinement and spheroidization of primary α(Al) grains.采用蛇形通道浇注工艺制备半固态6061铝合金浆料。研究浇注温度、弯道数量和弯道内径对显微组织的影响,并分析半固态浆料在浇注过程中的显微组织演变机理。结果表明:控制浇注温度在液相线附近可以细化晶粒、提高晶粒圆整度,并且增加弯道数量和降低弯道内径可以有效增加初生α(Al)晶粒的形核率。初生晶粒不仅由合金熔体受激冷形核和异质形核作用直接形成,而且还由断裂的枝晶碎片演化而来;同时,熔体中的“自搅拌”效应可提高熔体与蛇形通道之间的热交换,也促进初生α(Al)晶粒的细化和球化。

关 键 词：6061 aluminum alloy semi-solid slurry serpentine channel microstructural evolution 

分 类 号：TG292[金属学及工艺—铸造]