均质化退火对3003/4004复层铝合金组织和性能的影响

Effect of homogenizing annealing on microstructure and properties of 3003/4004 aluminum alloy bimetal slab

研究了铝合金复层铸坯的均质化退火温度和退火时间对铸坯微观组织和力学性能的影响。微观组织分析结果表明:退火时间为7 h,退火温度为490℃时4004合金一侧的共晶硅形态由板片状变成细小的球状和短棒状,大大降低了变形抗力。当退火温度为490℃,退火时间从7 h延长到14 h时对微观组织的影响不大。退火时间为7 h,退火温度分别为490℃和510℃时,4004合金一侧的共晶硅也比铸态下细小,从而使变形抗力降低。力学性能的检测结果表明:经均质化退火后的4004合金一侧的布氏硬度显著降低,3003合金一侧的硬度值略有上升。根据抗拉强度与硬度的关系,给出了复合界面结合强度的估算公式。

Effect of homogenizing annealing temperature and time on microstructure and mechanical properties of 3003 /4004 aluminum alloy bimetal slab was studied. Microstructure analysis results show that the lamellar eutectic silicon in the 4004 alloy is changed to the small spherical and short rod eutectic after homogenizing annealing at 490 ℃ for 7 h,and the deformation resistance of the alloy is reduced. When the annealing temperature is 490 ℃,annealing time is extended from 7 h to 14 h,no significant change of the microstructure is observed. The eutectic silicon of 4004 alloy annealing at 510 ℃ for 7 h remains small so that its deformation resistance decreases compared to as cast alloy. Hardness of the 4004 alloy is significantly reduced and the hardness of the 3003 alloy slightly increases after homogenizing annealing. The prediction method of the composite interface bonding strength for the bimetal slab is proposed based on the experiment and the relationship between tensile strength and hardness of metal.