受控扩散凝固工艺凝固机理与调控机制研究进展

Research Progress in Solidification and Regulation Mechanism of Controlled Diffusion Solidification Process

利用铸造工艺成形液固区间较大的合金体系,有效细化初生组织并抑制热裂甚为关键。不同于传统的凝固,受控扩散凝固(Controlled Diffusion Solidification,CDS)能有效解决铝合金铸件近净成形过程中的热裂问题,并简化工艺流程,为其工业化应用提供可能。综述了CDS工艺过程机理的研究进展,总结了关键性过程(如混合、温度场和溶质场的重新分布,3种类型的形核等),并归纳了工艺参数(如前驱合金温度、初始质量比和混合速率等)对CDS组织非枝晶转化率的影响,最后总结了CDS凝固机理和调控机制现存问题,并对CDS工艺的未来发展方向进行了展望。

It is crucial to use casting process to form alloy system with large liquid-solid interval to refine the primary structure effectively and inhibit thermal cracking.In contrast to conventional solidification,Controlled diffusion solidification(CDS)can effectively solve the problem of thermal cracking during the near-net-shape casting of deformed aluminum alloys and simplify the process to provide the possibility of industrial application.The research progress in CDS process mechanism was reviewed,and the key events were summarized including mixing,redistribution of temperature and solute fields,three types of nucleation,and influence of process parameters such as precursor alloy temperature,initial mass ratio and mixing rate on the non-dendritic conversion rate of CDS were concluded.Finally,the problems exsiting in CDS solidification and regulation mechanism were presented,and the future development direction was prospected.