【摘要】 通过硬度、导电率检测及扫描/透射电子显微分析，系统探究均匀化退火工艺对Al-6.0Mg-0.4Mn-0.15Sc-0.1Zr合金铸锭组织性能的影响。结果显示，铸态组织中未见粗大含钪化合物，Sc、Zr以过饱和固溶体或细小弥散相的形式存在；晶粒呈等轴状，尺寸为40～60μm,此均匀组织得益于Sc的晶粒细化作用。均匀化退火温度低于300℃时，枝晶偏析消除不充分，导电率低，硬度提升有限；均匀化退火温度高于350℃时，Sc、Zr易粗化，恶化加工性能；均匀化退火工艺为(300～350)℃8 h时，可有效溶解非平衡相、减少偏析，同时抑制粗大相生成，此时合金导电率达峰值，硬度适中，组织均匀性最佳。(300～350)℃8 h为该合金适宜的均匀化退火制度，可为后续塑性加工与强韧化处理奠定良好组织基础。更多还原

【Abstract】 This study systematically investigates the effect of homogenization process on the Al-6.0Mg-0.4Mn-0.15Sc-0.1Zr alloy ingot through hardness testing, electrical conductivity testing, and scanning/transmission electron microscopy analysis. The results show that no coarse scandium-containing compounds are observed in the as-cast microstructure, and Sc and Zr exist in the form of supersaturated solid solution or fine dispersed phases. The grains are equiaxed with a size of 40 μm-60 μm, and this uniform microstructure is attributed to the grain refinement effect of Sc. In the optimization of homogenization process, when the temperature is below 300 ℃, the elimination of dendritic segregation is insufficient, resulting in low electrical conductivity and limited increase in hardness. When the temperature is above 350 ℃, Sc and Zr tend to coarsen, deteriorating the workability. While the treatment at 300 ℃-350 ℃ for 8 h can effectively dissolve the non-equilibrium phases, reduce segregation, and simultaneously inhibit the formation of coarse phases. At this time, the alloy achieves the peak electrical conductivity, moderate hardness, and the best microstructure uniformity. In conclusion, 300 ℃-350 ℃/8 h is the suitable homogenization system for the alloy, which can lay a good microstructural foundation for subsequent plastic processing and toughening treatment.更多还原