Under the laminar shearing caused by the roller, the arms of the original dendrites are then broken and distributed dispersedly into residual alloy liquid and form free grains.

• 随着辊-靴型腔内合金固相率的增加，游离晶在以枝晶方式生长过程中受到层流剪切作用， 二次枝晶臂断裂破碎形成自由晶；