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采用旋转流变仪研究了剪切速率和不同工艺(连续冷却和重熔加热)对半固态SCN-5H_2O(摩尔分数,%)透明模型合金流变性与微观组织的耦合影响规律.结果表明,剪切速率的跃变升高会导致合金熔体的表观黏度呈现出暂态的剪切稠化和稳态剪切稀化现象.而随着剪切速率的增加,相应的组织呈现出非枝晶颗粒尺度逐渐减小,团聚体的分布更加分散的特征,但微观组织的形状因子随剪切速率变化不大.半固态合金熔体在重熔加热过程中的微观组织比连续冷却过程所获得的组织,颗粒尺度更大、形状因子略有减小,同时,团聚体的聚合作用更加强烈,这也导致合金熔体在重熔加热过程中的表观黏度高于连续冷却过程所获得的数值.
The influence of shear rate and different processes (continuous cooling and remelting heating) on the coupling of the rheological properties and the microstructure of semi-solid SCN-5H_2O (mol fraction,%) transparent model alloys was investigated by using a rotating rheometer. As the shear rate increases, the apparent viscosity of the alloy melt shows transient shear thickening and steady-state shear thinning, while the corresponding tissue shows non-branching The grain size of grains gradually decreases and the distribution of aggregates is more dispersed, but the shape factor of microstructure does not change much with the shear rate.The microstructure of semi-solid alloy melt during remelting heating is better than the continuous cooling process , The grain size is larger and the shape factor is slightly reduced. At the same time, the polymerization of agglomerates is more intense, which also leads to the apparent viscosity of the alloy melt during remelting heating is higher than that obtained by the continuous cooling process .