均匀化温度对6451铝合金显微组织及性能的影响

Effect of Homogenization Temperature on Microstructure and Properties of 6451 Aluminium Alloy

通过DSC、OM、SEM等设备研究不同均匀化温度下6451铝合金显微组织的演变过程。结果表明:随着均匀化温度的升高,6451铝合金铸态组织中的枝晶组织消失,Q-AlCuMgSi相回溶,Mg_(2)Si相先析出后回溶,Al(Fe,Mn)Si相由长条状发生断续化转变,形成长度更短、形状更圆润、尺寸更小的球状相。晶粒尺寸先增大后趋于稳定,530℃均匀化时晶粒尺寸由铸态时的164μm增大到213μm,温度继续升高,晶粒尺寸无明显变化。电导率呈现先升高后降低,趋于稳定后略微升高的现象。

The microstructure evolution of 6451 aluminium alloy at different homogenization temperature was studied by DSC,OM and SEM.The results show that with the increase of homogenization temperature,the dendrite structure in the as-cast structure of 6451 aluminium alloy disappears,the Q-AlCuMgSi phase redissolves,the Mg_(2)Si phase precipitates first and then redissolves,and the Al(Fe,Mn)Si phase discontinuously transforms from long strip to form a spheroidal phase with shorter length,more rounded shape and smaller size.At 530℃,the grain size increases from 164μm(as-cast)to 213μm.When the temperature continues to rise,the grain size does not change significantly.The electrical conductivity increases first and then decreases,and then increases slightly after stabilizing.