对流和弥散相液滴运动对偏晶合金凝固的影响

来源期刊：金属学报2009年第12期

论文作者：赵九洲 李海丽 赵雷

文章页码：1435 - 1440

关键词：偏晶合金； 液-液相变； 对流； 凝固

Key words：monotectic alloy； liquid-liquid phase transformation； convection； solidification

摘    要：偏晶合金非常广泛,许多具有重要的工业应用前景,但该类合金具有液态组元不混溶温度区间,当均一的合金熔体冷却进入组元不混溶温度区间时,它分解成两个液相,即发生液-液相变,因此,极易形成偏析严重的组织,这不仅限制了该类合金的制备,也为其凝固理论研究带来极大困难.研究表明,偏晶合金液-液相变过程十分复杂,影响因素众多,尤其是弥散相液滴运动和基体熔体对流使各影响因素相互混淆,致使偏晶合金凝固组织演变过程研究极为困难.综述了弥散相液滴运动和基体熔体对流对偏晶合金液-液相变过程的影响及研究现状.

Abstract: Many alloys show a phase diagram characterized by the appearance of a miscibility gap in the liquid state.Some of them have great potentials to be used in industry.But when a homogeneous,single-phase liquid is cooled into the miscibility gap,the components are no longer miscible and two liquid phases develop.Generally the liquid liquid decomposition causes the formation of the microstructure with serious segregation.The microstructure evolution during the liquid-liquid phase transformation of monotectic alloys is a result of the common actions of many factors.It is very complex,especially the convection of the matrix and the motion of the minority phase droplets might mix things up and make it extremely difficult to investigate the solidification process of monotectic alloys.In this paper,the effects of convection and minority phase droplet motion on the solidification of monotectic alloys were introduced;the current situation of researches in this field was overviewed.