1060铝套管包覆轧制AZ91镁棒的界面扩散行为研究

Study on interfacial diffusion behavior of AZ91 Magnesium bar rolled by 1060 aluminum casing coated

本文开展了1060铝套管包覆轧制AZ91镁棒的界面扩散行为研究,分析了不同轧制压下率和扩散化退火机制的界面扩散行为.实验结果表明:随着压下率的增大,复合界面处的裂纹宽度逐渐减小,压下率为88%时裂纹消失;经过扩散退火后,裂纹宽度减少,压下率为74%的试样裂纹间距缩小,压下率为83%的试样裂纹完全愈合.退火前,Al和Mg之间的相互扩散深度都随压下率的增加而增加,Al在Mg中的扩散深度的变化率要稍大一些.退火后,Al和Mg之间的相互扩散深度相比于未退火前都有一定的增加,退火时温度升高,界面原子的活动能力增强,增加Al和Mg之间相互扩散的深度.在88%大变形下才能形成良好的铝镁结合界面,结合界面处无氧化物产生.扩散化退火后,铝镁之间相互扩散,Al在Mg中的扩散深度较深,而Mg在Al中的扩散深度较浅.

The interfacial diffusion behavior of AZ91 magnesium bar rolled by 1060 aluminum casing coating has been studied in the text.The interfacial diffusion behavior under different rolling down rates and diffusion annealing mechanisms has been analyzed.The experimental results show that with the increase of down rate,the crack width at the composite interface decreases gradually,and the crack disappears when the down rate is 88%.After diffusion annealing,the crack width decreases,the crack spacing decreases when the down rate is 74%,and the crack heals completely when the down rate is 83%.Before annealing,the diffusion depth between Al and Mg increases with the increase of down rate,and the change rate of diffusion depth of Al in Mg is slightly larger.After annealing,the inter-diffusion depth between Al and Mg increases by comparing with that before annealing.The temperature is higher during annealing,and the mobility of the interface atoms is enhanced,resulting in an increase in the depth of inter-diffusion between Al and Mg.Good Al—Mg bonding interface can be formed under 88%large deformation,and no oxides can be produced at the inter-face.After diffusion annealing,Al and Mg diffuse mutually,Al diffuses deeply in Mg,while Mg diffuses shallowly in Al.