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采用石墨质蛇形通道制备半固态A380铝合金浆料,并研究浆料制备过程中浆料组织的演变.结果显示,合金熔体在蛇形通道内发生一次凝固,在其通道内壁的激冷和异质形核作用下形成大量的初生自由晶,半固态浆料的剩余液相在收集坩埚内发生二次凝固形成二次非枝晶.初生晶粒的游离模型表明一部分初生自由晶直接生长为球晶,其他部分则成长为枝晶,枝晶在“自搅拌”的作用下发生缩颈和熔断,通过“自旋转”在蛇形通道内得到初步球化和熟化.二次凝固形成的二次非枝晶在收集坩埚内得到初步球化和熟化,同时初生晶粒在收集坩埚内得到进一步球化、熟化和均匀分布.
The semi-solid A380 aluminum alloy slurry was prepared by using graphite serpentine channel and the evolution of slurry microstructure during the preparation of the slurry was studied.The results show that once the alloy melt solidified in the serpentine channel, And heterogeneous nucleation, a large number of primary free crystals and the remaining liquid phase of semi-solid slurry formed in the collecting crucible secondary solidification to form secondary non-dendrites.The free-form of the primary grains showed that some of the primary free crystals grow directly Spherulites, other parts of the growth of dendrites, dendrites in the “self-stirring” under the effect of necking and melting, through the “spin” in the serpentine access to the initial ball and maturation. The secondary non-dendrites formed by the secondary solidification are initially spheroidized and aged in the collection crucible while the primary crystal grains are further spheroidized, aged and uniformly distributed in the collection crucible.