【作者】 管刘辉；

【导师】 李宝绵；

【作者基本信息】 东北大学 ， 材料加工工程， 2008， 硕士

【摘要】 通过热轧轧制复合的方法获得了AL1050/AZ31/AL1050三层复合板。研究了轧制温度、压下率对复合板的结合强度的影响,以及轧后退火工艺对复合板的结合强度及界面结构的影响；探讨界面结合机理,确定出最佳工艺方案。实验结果表明：其他条件相同情况下,复合板的结合强度随着轧制温度先升高后下降。其他条件相同情况下,复合板的结合强度随压下率的增加而升高,但当压下率过大时,复合板会出现较大程度的裂边。综合考虑复合板的结合强度和表面质量,最佳轧制复合工艺参数：加热温度控制在410～430℃、压下率控制在50～60%。在此工艺条件下,复合板表面质量良好,没有明显褶皱,复合板的结合强度为45～50MPa,复合板经过弯曲扭转实验后,没有明显的开裂和分离现象。轧制复合后适当的扩散退火处理可进一步改善复合板的结合强度、力学性能和成形性能。若退火工艺控制不当,界面会形成脆性化合物导致复合板的结合强度急剧下降。实际生产中,建议扩散退火制度为：退火温度250℃,退火时间30min。退火时出现的两脆性化合物层,通过电子探针成分分析,以为靠镁基体侧化合物为Mg17Al12,靠铝基体侧化合物为Mg2Al3。轧制压下率对铝层和镁层的变形分配有影响,而轧制温度对铝层和镁层的变形分配率影响很小。随轧制压下率的增加,铝层和镁层的变形程度均增大,但变形分配上铝层增大的快。轧制复合过程中发生的裂口机制、嵌合作用机制,实现了复合板初始的机械结合。热作用机制的启动和发育是复合板的结合强度高的主要因素。另外,扩散机制在一定程度上对复合板的结合强度也有所提高。更多还原

【Abstract】 Pure aluminum/magnesium/pure aluminum clad plates were fabricated by the hot rolling method. The effects of rolling temperature, pass reduction on the interfacial bonding strength were researched; and the effect of the subsequent annealing process on the interfacial bonding strength and the joint interface structure were investigated. The bonding mechanism was discussed, and then the optimal roll cladding parameters were given.It is shown that when other conditions are same, with the increase in rolling temperature the bonding strength increase first then decrease. With the increase in pass reduction the bonding strength increases, but the checked edge occurs when the pass reduction is high. The optimal roll cladding parameters are determined as:rolling temperature is 410-430℃, pass reduction is 50-60%. At such conditions, the interfacial bonding strength is about 45-50MPa and the process property of the clad strip is good.Appropriate subsequent annealing can improve bonding strength to some extent, but brittle compound forms and the bonding strength reduces sharply if the annealing temperature is too high or the annealing time is too long. The optimal annealing parameters are determined as:annealing temperature is 250℃, annealing time is 30 minutes. The reaction phases are estimated by EPMA analysis to be Mg17Al12 in the magnesium side and Mg2Al3 in the pure aluminum side.Rolling temperature has effect on the deformation amount of each component layer, while pass reduction has little effect. With the increase in pass reduction the deformation amount of both aluminum and magnesium layer increases, but the deformation amount of magnesium layer is much greater than that of aluminum layer.Cracking mechanism and inlaying mechanism take place during roll bonding and make the initial mechanical bond. The initiation and evolution of heat effect mechanism is the main factors leading to the high bonding strength. The inter-diffusion mechanism as well as can improves bonding strength to some extent.更多还原