冷却速率对Al-50%Si合金微观组织的影响  

Effect of cooling rate on microstructure of Al-50%Si alloy

作　　者：张真[1] 张雨生 孔喆灏 陈欢欢 黄魏楼 胡先德 魏海根 ZHANG Zhen;ZHANG Yusheng;KONG Zhehao;CHEN Huanhuan;HUANG Weilou;HU Xiande;WEI Haigen(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;Anqing Art TP Pistons Co.,Ltd.,Anqing 246000,China;Anhui Vocational and Technical College,Hefei 230011,China)

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009 [2]安庆雅德帝伯活塞有限公司,安徽安庆246000 [3]安徽职业技术学院,安徽合肥230011

出　　处：《有色金属材料与工程》2024年第4期58-65,共8页Nonferrous Metal Materials and Engineering

基　　金：安徽省重点研究与开发计划项目(202104a05020047,2022a05020032);合肥工业大学智能制造技术研究院科技成果转化及产业化重点项目(IMICZ2019003)。

摘　　要：采用熔体水淬法(水冷法)、气雾化法和单辊熔融纺丝技术(甩带法)制备不同冷却速率的快速凝固过共晶Al-50%Si合金,并通过扫描电子显微镜(scanning electron microscope,SEM)和X射线衍射仪(X-ray diffractometer,XRD)分析了快速凝固与常规凝固的差异,以及快速凝固Al-50%Si合金微观组织的演变。结果表明:在水冷的Al-50%Si合金组织中观察到了树枝状的Al相,较大的过冷度导致这种亚共晶组织的形成,此组织属于非稳定状态,且共晶Si完全细化至纤维状;随着冷却速率的增加,在甩带试样中Al相的树枝状组织消失;通过甩带以及气雾化制备的Al-50%Si合金中,初晶Si颗粒被明显细化,由常规凝固的200μm细化至20μm左右,使Si在Al基体中的固溶度增大,造成Al基体晶格发生畸变。The hypereutectic Al-50%Si alloys were prepared by water-cooling,gas atomization and single roll melt spinning technique in this work.The differences between rapid solidification and conventional solidification were analyzed by means of scanning electron microscope and XRD techniques,and the microstructural evolution of the rapid solidification Al-50%Si alloys was studied.The results showed that the dendritic Al phases were observed due to large undercooling degree in rapid solidification Al-50%Si alloys by water cooled,which induced non-equilibrium hypoeutectic Al-Si microstructures and fibrous eutectic silicon.As the cooling rate increased,the dendritic-shape of Al phase disappeared in rapid solidification ribbon by single roll melt spinning technique.the primary Si particle was refined significantly from 200μm to 20μm in the Al-50%Si alloys fabricated by gas atomization and single roll melt spinning technique.And the solid solubility of silicon in Al matrix was increased,which caused the lattice distortion of the Al matrix.

关 键 词：高硅铝合金 冷却速率 快速凝固 非平衡凝固 固溶度 

分 类 号：TG[金属学及工艺]