快速凝固Al-21Si-0.8Mg-1.5Cu合金时效析出行为  

Aging precipitation behavior of rapidly solidified Al-21Si-0.8Mg-1.5Cu alloy

作　　者：王爱琴[1,2] 谢敬佩[1] 王文焱[1] 李继文[1] 李洛利[1] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南省有色金属材料科学与加工技术重点实验室,河南洛阳471003

出　　处：《材料热处理学报》2013年第1期86-89,共4页Transactions of Materials and Heat Treatment

基　　金：河南省国际科技合作项目(084300510006);河南科技大学博士科研基金(2008bs025)

摘　　要：利用单辊旋转甩带法制备快速凝固过共晶Al-21Si-0.8Mg-1.5Cu合金条带,并对其进行时效处理,采用扫描电镜、透射电镜及XRD技术对快速凝固组织特征进行了表征,研究了时效温度对合金组织及硬度的影响。结果表明:在快速凝固条件下,试验合金中初生硅相的形核和析出受到抑制,α相领先析出,合金元素Cu、Mg全部固溶在过饱和α-Al固溶体中;大量的Si过饱和固溶于α中,其余部分以羽毛针列状共晶形式析出,形成微纳米级亚稳的亚共晶结构。时效处理时,随着时效温度的升高,硅元素从基体中脱溶析出并逐渐聚集长大,形成微小颗粒弥散基体之上;试验合金的显微硬度也发生了变化,出现时效硬化现象。A rapidly solidified hypereutectic A1-21Si-0. 8Mg-1.5Cu alloys strip was prepared by single roller melt-spinning method. The resultant strip was aged at different temperatures for 4 h. Microstructure of the rapidly solidified alloy was characterized by means of scanning electron microscopy （SEM） , transmission electric microscopy （TEM） and XRD. The effects of aging temperature on the microstructure and microhardness of the experimental alloy were investigated. The results show that the nucleation and growth of primary silicon are suppressed, meanwhile, α-A1 phase is nucleated, which is prior to eutectic under rapidly solidification. All alloying elements Cu and Mg are supersaturated in α-A1 solid solution. Most of Si is supersaturated in α-A1, the rest precipitated by feather-needles-like eutectic silicon micro-nanocrystals. The metastable hypoeutectic structure is formed. During aging process, silicon element is precipitated from the matrix and gradually aggregated up to form small particles distributed in the matrix as the increase of aging temperature. The hardness of experimental alloy is changed, and age-harden phenomenon occurs.

关 键 词：快速凝固 过共晶铝硅合金 微观组织 时效析出 显微硬度 

分 类 号：TG146.2[一般工业技术—材料科学与工程]