李春,范新会.Mg-16Zn-5Al合金部分重熔过程中的组织和相演变机制[J].稀有金属材料与工程,2018,47(7):2072~2079.[Li Chun,FAN Xinhui.Microstructure and Phase Evolution Mechanism during Partial Remelting of Mg-16Zn-5Al alloy[J].Rare Metal Materials and Engineering,2018,47(7):2072~2079.]
Mg-16Zn-5Al合金部分重熔过程中的组织和相演变机制
投稿时间:2018-01-03  修订日期:2018-07-06
中文关键词:  Mg-16Zn-5Al合金  组织演变  相转变  部分重熔  半固态成形
基金项目:国家自然科学基金(51464031);陕西省教育厅专项科研计划资助项目(16JK1241); 商洛市科技计划项目(SK2016-29)
中文摘要:
      研究了Mg-16Zn-5Al合金在部分重熔过程中的演变演变和相转变。结果表明:Mg-16Zn-5Al合金在440℃重熔30~60min或460℃重熔30min可获得理想的半固态球晶组织,其平均晶粒尺寸为54.9~57.9μm,平均圆整度为1.18~1.29,固相率约为65%。合金在重熔过程中发生的相转变(即:MgZn+τ→α-Mg、α-Mg+MgZn+τ→L、α-Mg→L及α-Mg→L和L→α-Mg)导致了晶粒内部的快速粗化合并、组织分离、球化和后期的吞并粗化,同时晶粒内部的亚晶界和根部重熔对组织的分离起着重要作用。基于LSW理论推导出了某一保温时间段内与扩散系数相关的晶粒粗化因子Mn,用其描述晶粒在相应阶段的主要演变方式。
Microstructure and Phase Evolution Mechanism during Partial Remelting of Mg-16Zn-5Al alloy
英文关键词:Mg-16Zn-5Al alloy  microstructure evolution  phase transformation  partial remelting  semi-solid forming
英文摘要:
      The microstructure evolution and phase transformation of Mg-16Zn-5Al alloy were investigated during partial remelting. Results show that when remelting parameter is 440℃+(30~60min) or 460℃+30min, Mg-16Zn-5Al alloy can obtain the idea semi-solid spherical microstructure. The average grain size is 54.9~57.9μm, and the average roundness is 1.18~1.29, and the solid fraction is about 65%. The phases transformation which include MgZn+τ→α-Mg, α-Mg+MgZn+τ→L, α-Mg→L, α-Mg→L and L→α-Mg were occurred during partial remelting. They lead to the initial rapid coarsening of the grain, structure separation, spheroidization of the grain and final merger coarsening. Meanwhile, the subboundary and root remelting within the alloy play an important role in separation of microstructure. The coarsening factor Mn which related with diffusion coefficient at a isothermal period was deduced by LSW theory. The main evolution way of grain is described by Mn at corresponding period.
作者单位E-mail
李春 商洛学院 lic_slxy@163.com 
范新会 商洛学院 fxh_slxy@163.com 
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