半固态/液态双金属复合铸锭的界面凝固行为研究

项目名称： 半固态/液态双金属复合铸锭的界面凝固行为研究

项目编号： No.51474091

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 矿业工程

项目作者： 郑小平

作者单位： 华北理工大学

项目金额： 80万元

中文摘要： 液/液复合技术因可实现牢固冶金结合的界面，而成为制备双金属复合材料的重要手段；但其界面宽度可控性和稳定性差，阻碍了其技术的进一步发展与应用。而低温的半固态金属浆料具有较高的黏度，与高温金属熔体的对流、扩散能力相对较低，则有利于控制两者形成的冶金结合界面宽度和连续稳定性。本项目旨在利用半固态金属浆料与液态金属熔体同时浇注，并连续铸造出具有半固态显微组织/枝晶组织特征的AZ91D/6061双金属复合铸锭，其界面宽度易调控，且界面强度高、无缺陷，连续稳定；重点研究半固态金属浆料特性、铸造工艺参数与界面形态的相互关系，探讨半固态/液态复合技术制备双金属复合材料的界面凝固机理，为半固态/液态 金属同时浇注连续铸造技术制备高性能双金属复合材料提供理论依据和关键技术。本项目的实施不但为制备双金属复合材料开辟一条新途径，而且丰富了冶金界面的形成理论，还将深化对金属材料凝固规律的认识。

中文关键词： 连续铸造；凝固行为；组织演变；镁合金；铝合金

英文摘要： The interface with metallurgic bonding can be obtained by the liquid/liquid compound technology. And this technology became a important preparation method for the bimetallic composites. But the development and application of the technology have be hinder by the interface defects of uncontrollable interface width and discontinuous interface. And the semi-solid metal slurry have the characteristics of high viscosity and low temperature. If the extent of convection and disffusion between the semi-solid metal slurry and the molten metal was decreased, the controllable interface width and continuous interface would be realized. In this project, a kind of AZ91D/6061 bimetallic composites ingots with semi-solid microstructures will be prepared by continuous casting with the semi-solid slurry and the molten metal pouring (semi-solid/liquid pouring continuous casting). Otherwise, the interface with high strength, zero defect, continuous stability and controllable interface width will be obtained by the technology. And then, the relationship between microstructure characteristics, processing parameters and interface morphology will be preferential investigated, the bonding mechanism of the bimetallic composites prepared by the semi-solid/liquid pouring continuous casting technology will be studyed. If this project was implemented, a new technology for the bimetallic composites would be developped and the formation theory of the metallurgic bonding interface would be expanded.

英文关键词： continuous casting;solidification behavior;microstructure evolution;magnesium alloy;aluminum alloy