论文部分内容阅读
用半固态金属流变模型研究了Al-6.5Si(质量分数,％)体系的稳态和暂态流变行为。分析表明,半固态金属的流变行为与其微结构有很强的关联,在固相体积分数一定的情况下,体系的表观粘度完全由其微结构所决定,而剪切速率和剪切时间对表观粘度的影响是通过改变体系的微结构来实现的。稳态粘度随固相体积分数的增加而增加、随剪切速率的增加而减小,这与文献中的实验结果相符合;体系的解聚过程比聚集过程快两个数量级。在各种形变条件下所出现的滞后环的大小由上升时间、静置时间、原初剪切速率、最大剪切速率等因素决定。
The semi-solid metal rheological model was used to study the steady-state and transient rheological behavior of Al-6.5Si (mass fraction,%) system. The analysis shows that the rheological behavior of semi-solid metal is strongly related to its microstructure. Under certain volume fraction of solid phase, the apparent viscosity of the system is completely determined by its microstructure. The shear rate and shear time The effect on apparent viscosity is achieved by changing the microstructure of the system. The steady state viscosity increases with the volume fraction of the solid phase and decreases with the increase of the shear rate, which is consistent with the experimental results in the literature. The depolymerization process of the system is two orders of magnitude faster than the aggregation process. The magnitude of the hysteresis loop occurring under various deformation conditions is determined by such factors as rise time, standstill time, primary shear rate, and maximum shear rate.