锰结合熔体保温对铝硅合金中富铁相特征的影响  

Iron-Rich Phase Morphology Characteristics for Al-Si Alloy by Mn Addition and Melt Holding

作　　者：宋东福 王顺成 周楠 徐静 郑开宏 Song Dongfu Wang Shuncheng Zhou Nan Xu Jing Zheng Kaihong(Guangdong Institute of Materials and Processing, Guangzhou 510650, China)

机构地区：[1]广东省材料与加工研究所,广东广州510650

出　　处：《稀有金属》2017年第7期739-744,共6页Chinese Journal of Rare Metals

基　　金：广东省科技厅科技计划项目(2014B030301012;2015B090926013;2014B090903005;2014B090903016;2013B091601001;2013B091601002);广州市科技计划项目(201509010003;201604010104)资助

摘　　要：在含1.0%Fe(质量分数)的A356铝合金中加入1.2%Mn(质量分数),经850℃熔化后降至615~680℃保温1 h。采用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)等现代研究手段研究保温温度对富铁相形态特征的影响规律,并探讨富铁相的形成机制。研究结果表明:随着保温温度的降低,合金组织细化效果逐步提升,富铁相分布均匀性增加;富铁相形态随温度降低的演变顺序为:星型+细网状→多边形(4~6)+汉字状→多边形(3~4)+汉字状+细网状→多边形(细小)+汉字状→汉字状;富铁相中的(Mn,Fe)/Si原子分数比值主要取决于富铁相的形态,而富铁相中Mn/Fe原子分数比主要取决于保温温度;统计数据发现,较低温度保温能有效降低富铁相的含量和细化富铁相尺寸,降低幅度分别达到62.6%和42.1%,而其余富铁相则以粗大的、圆整度高的多边形富铁相沉降在炉底。1.2. % Mn（ mass fraction） was added in A356 aluminum alloy which contained 1.0% iron（ mass fraction）, then the tem- perature of the metal melt was decreased to 615 - 680 ℃ and held for 1 h after melting at 850 ℃. The effects of melt holding tempera- ture on the morphology of iron-rich phase for A1-Si alloy were investigated by optical microscope （ OM ）, scanning electron microscope （ SEM）, energy disperse spectroscopy （EDS） and other modern research tools, and the formation mechanism of iron-rich phase was al- so discussed. The results showed that, with the decrease of holding temperature, refinement effect of alloy microstructure and uniformi- ty of iron-rich phase were improved gradually. The evolution sequence of iron-rich phase morphology with holding temperature was ： star ＋ fine-mesh→polygon （4 - 6 ） ＋ Chinese script→polygon （ 3 - 4 ） ＋ Chinese script ＋ fine mesh→polygon （fine） ＋ Chinese script→Chinese script. （ Mn, Fe）/Si ratio of iron-rich phase depended on its morphology, while Mn/Fe ratio depended primarily on the hold- ing temperature. Moreover, the statistics data revealed that lower holding temperatures could reduce the content and size of iron-rich phase by 62.6% and 42.1% respectively, while the other iron-rich phase deposited in the bottom in the form of coarse and highly rounded polygon.

关 键 词：熔体保温 铝硅合金 富铁相 形成机制 

分 类 号：TG146[一般工业技术—材料科学与工程]