退火对AZ91/1060爆炸复合板界面的影响

Effect of Annealing on Bonding Interface of AZ91/1060 Explosive Welding Composite Plates

将AZ91镁合金/1060纯铝爆炸复合板进行退火处理,对热处理前后结合界面处的显微组织、成分分布、力学性能进行分析和研究。结果表明,退火过程中镁元素易于向纯铝中扩散,扩散层主要位于靠近界面的纯铝中;退火后的复合板界面处的扩散层厚度和最高硬度均比未热处理时有明显提高,高硬度层从原始复合板界面的镁合金一侧转移到纯铝一侧,原始复合板中引起界面处硬度升高的原因是加工硬化效应,热处理后界面处的高硬度是由于在扩散层中产生镁-铝固溶体和金属间化合物;随着退火温度的升高,界面处扩散层厚度增加,组织中发生再结晶趋势增强,形变带逐渐消失。

AZ91 Mg alloy/1060 pure Al explosive composite plates were annealed.The microstructures,element distributions and mechanical properties of the bonding interfaces before and after annealing were studied.The results show that Mg atoms diffuse from AZ91 to 1060 during the annealing process and the diffusion layer is in 1060 near the interface.The thickness of diffusion layer and the highest hardness of composite plates increase obviously after annealing.The high hardness layer is in AZ31 near the interface in composite plates before annealing;however after annealing the high hardness layer is in 1060 near the interface.The hardness increase before annealing results from work hardening while the hardness increase after annealing is attributed to solid solution and intermetallic compounds formed in diffusion layers.With the increase of annealing temperature,the thickness of diffusion layers increases,recrystallization tendency is more obvious and deformation bands disappear gradually.