连续铸挤铝包钢线复合机理

BONDING MECHANISMS OF AS WIRE BY CASTEX

铝包钢线是一种性能优异的架空导线用材。为了改变我国铝包钢线国产化低的局面，探索铝包钢线的加工方法，开发了一种高效节能节材的半固态／固态复合加工工艺———连续铸挤工艺生产铝包钢线，并在实验基础上对该工艺的铝钢复合机理进行了深入细致的研究。研究表明，在铝钢焊合室存在３个复合阶段：压紧阶段，主要存在压合机制及较弱的铝热机制；复合阶段，主要存在压合机制、强烈的铝热机制和扩散机制；定径阶段，主要存在压合机制及较弱的铝热机制和扩散机制。其中铝热机制的作用尤为重要，当温度高于３５０℃时，该机制才能发生。

AS wire is a kind of excellent materials for overhead line. A new method, Castex, to produce AS wire was investigated, which is characterized by high efficiency and low energy cost for composite of semi solid metal/solid metal. Based on experimental results, the bonding mechanism of Al and steel by Castex in the bonding stage was studied. The results showed that there exist three stages in the bonding container, i.e., pressing stage, which mainly composes pressing mechanism and weak thermit mechanism; bonding stage, which mainly composes pressing mechanism, strong thermit mechanism and diffusion mechanism; sizing stage, which mainly composes pressing mechanism, weak thermit mechanism and diffusion mechanism. Among them the thermit mechanism is most important, which will take place when the temeprature is above 350 ℃.