金属液海绵模型的探讨  

Discussion about Sponge Model of the Molten Metal

作　　者：孙少东[1] 何时剑[1] 张孟群[2] 刘笛[2] 

机构地区：[1]淮安信息技术学院机电工程系,江苏淮安223001 [2]南京大学现代分析中心,江苏南京210018

出　　处：《铸造技术》2010年第7期873-876,共4页Foundry Technology

摘　　要：通过对球墨铸铁件表面及横截面上含镁量的测定,发现球铁铸件不同方向的表面上镁的百分含量相同,且明显地高于铸件的平均成分,从铸件表面到心部的横截面上镁的百分含量不相同,呈现梯度增加的分布状态。按照传统的液态物理模型观念,金属液中的气泡由于浮力的作用总是上浮到金属液或铸件的上表面,应该造成铸件上表面较其它方向的表面具有更高的含镁量,但这与实验结果相违背。为此,提出了金属液海绵模型的设想,分析与讨论的结果表明,金属液海绵模型较传统的液态物理模型更加有助于解释金属液冷却过程中气泡迁移问题。Through testing the chemical composition of Mg on the surface and the cross section of a ductile iron casting, it is found that different directional surfaces has the same percentage content of Mg, and all significantly higher than the average composition in the casting. Moreover, it is also found that the percentage content of Mg from the surface to the center of the casting is gradient increased. According to the traditional concept of physical model of liquid, the bubble in the molten metal would always float to the top surface of the casting as the role of buoyancy. Because of this, the top surface of the casting would show higher percentage content of Mg than that of the side or bottom surface. This is obviously contrary to the experimental results. With regards to this, this paper presents the idea of liquid metal sponge model, analyzing and discussing of the results showed that the liquid metal sponge model is more helpful to explain the bubble migration issues in the cooling process of the liquid metal.

关 键 词：金属液 海绵模型 气泡迁移 挤压力 

分 类 号：TG255[金属学及工艺—铸造]