本文在定向凝固系统上用变速抽拉方法试验研究了Al-Si共晶强制非稳态生长过程。在加速生长过程中,共晶相间距对生长速度的响应呈滞后效应,响应机制是共晶Si相成簇分枝和局域“终结”延伸。在减速生长过程中,Si相成簇分枝和“终结”伸缩机制仍控制相间距;共晶相间距由初始生长速度决定,对生长速度下降不产生响应。 In this paper, a variable speed pull-out method was used to study the forced unsteady growth process of Al-Si eutectic on a directional solidification system. In the process of accelerated growth, the response of eutectic spacing to the growth rate has a hysteresis effect, and the response mechanism is the clustering of eutectic Si phases and the local “terminal” extension. During slow growth, Si phase clustering and “terminal” stretching mechanism still control the phase spacing; the eutectic phase spacing is determined by the initial growth rate and does not respond to the growth rate decrease.