【摘要】 实验研究了镁合金半固态铸轧的组织。铸轧试验是在一台自制的铸轧试验机上进行。试验结果表明,铸轧对半固态镁合金组织有显著的影响。铸轧前的半固态镁合金是由机械搅拌制备,组织中先结晶的固相颗粒形状不规则,有枝晶的痕迹;然而铸轧后组织中,先结晶的固相颗粒形状变得非常圆整,接近球形。基于试验结果,提出了半固态铸轧对一次相颗粒的圆整化机制。认为铸轧对半固态组织的圆整化作用是通过固液两相相对流动摩擦消除尖角而圆整化或固相颗粒翻滚破碎重叠合并而圆整化两种方式实现的。此外,在一定的工艺条件下,凝固的金属在进一步的轧制变形中,圆整的球形一次相颗粒被轧制变形,变成为椭球状。更多还原

【Abstract】 The paper investigated the microstructure of the semi-solid magnesium alloys by casting-rolling.The experiment of the casting and rolling of semi-solid Magnesium alloy was carried out on the equipment made by ourselves in our laboratory.It was found that casting and rolling have a remarkable effect on the microstructure of semi-solid Magnesium alloy.The slurry was gotten by the mechanical stirring before casting and rolling in which the first crystallized particle was not regular and remain the dendritic shape;but after casting and rolling the first crystallized particle in the microstructure becomed regular and near to ball.According to this fact,a new ball-regularization mechanism to semi-solid state by casting-rolling was put up.There was two ways to function:one is the friction between solid phase and liquid phase;the other is the rolling of the solid particle and crashing or combining which both leads to the solid particle changing into the ball.更多还原