不同淬火冷却介质对高锌7系铝合金组织性能的影响

Effects of Quenching Mediums on Microstructures and Mechanical Properties of 7 Series Al Alloys with High Zn Content

采用透射电镜组织观察和力学性能测试,研究了3种淬火冷却介质对含Zn量为8.9%的7系铝合金力学性能和微观组织的影响。研究表明采用室温水淬火冷却,T6时效后合金强度硬度最高、晶内细小弥散析出相最多、粗大平衡相最少;采用空气淬火冷却,T6时效后合金强度硬度最低、晶内析出的粗大平衡相最多;采用沸水冷却淬火T6时效,合金强度硬度介于空冷淬火和室温水淬火之间,晶内粗大析出相的量少于空冷淬火。

The effects of three quenching mediums on microstructures and mechanical properties of 7 series Al alloys（with 8.9% Zn content） have been investigated by transmission electron microscope（TEM） and mechanics properties testing.When the quenching medium is room-temperature water,the tensile strength and hardness of the studied alloy are the highest,and the quantity of the fine precipited phase is the largest while that of the coarse equilibrium phase is the smallest after T6 ageing.The tensile strength and hardness of the studied alloy after T6 ageing are the lowest while the quantity of the coarse equilibrium phase is the largest when air is used as the quenching medium.When boiling water is used for quenching,after T6 ageing,the strength and hardness of the alloy is between those of dry quenching and room-tempeature quenching while the quantity of the coarse equilibrium phase is smaller than that of the dry quenching.