蛇形通道浇注法制备半固态A390合金浆料

Preparing Semi-solid A390 Alloy Slurry Though Serpentine Channel Pouring Process

采用蛇形通道浇注法制备了半固态A390合金浆料,并探讨了A390合金中初生硅的细化机理。结果表明,蛇形通道浇注法能够制备优良的半固态A390合金浆料,尤其当浇注温度为690℃时,浆料组织中初生硅可获得充分细化,初生硅的等效圆直径为19.7μm,平均形状因子为0.7。蛇形通道内壁的激冷促进了初生硅的形核,并细化了初生硅;合金熔体的冲刷促使了初生硅的游离,进一步细化了初生硅。因此,蛇形通道浇注法可细化A390合金中初生硅,无需任何化学细化处理,为A390合金中初生硅的细化提供了一种新的工艺方法。

The serpentine channel pouring process for preparing semi-solid A390 alloy slurry was used and mechanism of refinement of the primary Si in A390 alloy was investigated. The results show that preparing semi-solid A390 alloy slurry with high quality through serpentine channel pouring process is feasible, especially when the pouring temperature is 690℃, the primary Si grains of slurry are refined to the greatest extent and the equivalent grain diameter and the average shape factor of the primary Si were 19.71J m and 0.7. The primary Si nucleus could be easily precipitated due to chilling effect of the channel inner wall, thus the primary Si grains are refined; meanwhile, the alloy melt fluid also promote the separation of primary Si grains from the inner wall, further refining the primary Si grains. Therefore, the primary Si grains of A390 alloy could be refined by the serpentine channel pouring process, which offere a new process method for refining the primary Si grains of A390 alloy without any chemical refinement operation.