【摘要】 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。更多还原

【Abstract】 Nonstable growth of Al-Si eutectic in constrained condition has beeninvestigated by means of change of the pulling velocity in an unidirectional solidi-fication system. In constant acceleration growth, a retard effect of response of eu-tectic interflake spacing on the growth rate has been observed. However, in cons-tant deceleration growth, the interflake spacing is determined by the initial growthrate and does not response to the decreasing of growth rate.更多还原