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。
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 40μm-60μm,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.
作者
陈雷
路丽英
徐畅
雷金琴
胡天龙
王海彬
陈岩
杨佳楠
姜锋
CHEN Lei;LU Liying;XU Chang;LEI Jinqin;HU Tianlong;WANG Haibin;CHEN Yan;YANG Jianan;JIANG Feng(Northeast Light Alloy Co.,Ltd.,Harbin 150060,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)
出处
《轻合金加工技术》
2025年第12期50-57,共8页
Light Alloy Fabrication Technology
基金
国家重点研发计划项目(2024YFB3714002)。
