La、Zr微合金化对Al-5Mg-0.2Ti合金微观组织和力学性能的影响  

Effect of La,Zr Micro-alloying on the Microstructure and Mechanical Properties of Al-5Mg-0.2Ti Alloy

作　　者：余爱武 杨成刚[1] 何鹏[1,2] 刘奋成[1] 王善林[1] 陈和[1] 

机构地区：[1]南昌航空大学,江西南昌330063 [2]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001

出　　处：《稀有金属材料与工程》2016年第3期760-764,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51165038;51201087);江西省教育厅科技计划项目(GJJ13496;GJJ12453);航空科学基金(2011ZE56005);南昌航空大学研究生创新基金项目(YC2013005)

摘　　要：采用铸锭冶金法制备了含稀土La和Zr的Al-Mg-Ti合金,通过力学性能测试及金相显微镜、扫描电镜、能谱和X射线衍射仪,观察分析了La、Zr微合金化对Al-Mg-Ti合金微观组织和力学性能的影响。结果表明,添加0.2%Zr能有效细化Al-Mg-Ti合金晶粒,说明Ti、Zr的细化作用是相容的,同时基体中析出的脆硬相Al_3Zr能显著提高合金硬度,但弱化了晶粒细化对合金强度和塑性的影响。0.2%La和0.2%Zr复合添加时的细化效果更为显著,合金的平均晶粒尺寸仅为55μm,同时La的添加有效避免了脆硬相Al_3Zr的析出和粗化,使合金的强度和塑性都得到了显著的提高,而硬度变化较小。Al-Mg-Ti alloys containing La and Zr elements were prepared by cast metallurgy.Effects of La and Zr additions on microstructure and mechanical properties of Al-Mg-Ti alloy were investigated by mechanical property test,optical microscopy,scanning electron microscopy,energy spectrum and X-ray diffraction.The results show that the addition of 0.2%Zr can positively refine the grain size,which indicates the composite refining effect of Ti and Zr is compatible,and the brittle phases of Al_3Zr precipitated in matrix can significantly increase the hardness of the alloys,but weaken the effect of grain refinement on the strength and ductility of the alloy.The combined addition of 0.2%La and 0.2%Zr possesses the excellent grain refining effect,when the average grain size of the alloy drops to only about 55 μm and the addition of La effectively avoids the precipitation and coarsening of brittle phase of Al_3Zr,thus improving the strength and ductility with the hardness changing slightly.

关 键 词：Al-Mg-Ti合金 微观组织 力学性能 脆硬相 

分 类 号：TG146.21[一般工业技术—材料科学与工程]