定向凝固技术的若干进展

Some Development of Directional Solidification Technique

定向凝固技术可使材料凝固组织按特定方向排列,获得定向及单晶组织结构,大大改善材料的力学和物理性能。简要地回顾了传统定向凝固技术的发展,指出了其存在温度梯度低的弊端。评述了几种新发展起来的新型定向凝固技术,并对其存在问题及发展趋势进行了讨论。指出电磁约束成形定向凝固技术集金属材料的加热熔化、无接触约束成形及组织定向凝固于一体,特别适合于高熔点、易氧化、高活性的特种合金坯件的无污染制备。

Directional solidification technique enables the solidification structure of materials to put in order along a specific direction, namely as the directional or single crystal structure, which could improve scientifically mechanical and physical properties of materials. The development of the traditional directional solidification technique has been reviewed briefly. It indicates that the traditional directional solidification techniques have the shortcomings with low thermal gradient. Some new technique of directional solidification and existing problems are discussed. The trends of developments of directional solidification technique are also prospected. Electromagnetic shaping integrates melting of metal, un-contact electromagnetic shaping of melt and controlling of solidification structure. It is considered to be suitable for shaping special alloys which are high melting-point, oxidizable and liable to react against mould material.