【摘要】 用半定量电子探针、扫描电镜、透射电镜方法,分析了单、双级均匀化对AA7150合金中Al3Zr分布的影响。结果表明,在铸态条件下Zr在枝晶心部浓度高,枝晶边缘处浓度低。在均匀化温度460°C下处理20h并不足以改变其浓度梯度。当均匀化温度达到460～480°C时,在枝晶心部可获得大量的Al3Zr弥散相,且Al3Zr弥散相的尺寸随着单双级均匀化处理温度的升高而增大。更多还原

【Abstract】 Semi-quantitative electron probe microanalysis (EPMA) mapping, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study the effect of one-step and two-step treatments on the Zr distribution and Al3Zr dispersoid characteristics in as-cast commercial AA7150 aluminum alloy. It is shown that the Zr concentration in the dendrite centre regions is higher than that near the dendrite edges in the as-cast condition, and that homogenization at 460 °C for 20 h is insufficient to remove these concentration gradients. After homogenizing at 460-480 °C, a high number density of larger dispersoids can be observed in dendrite centre regions but not near dendrite edges. Furthermore, the dispersoid size increases with increasing the temperature during both one-step and two-step homogenization treatments.更多还原