Mge3Lie0.4Zr alloys containing RE elements(Gd,La,Nd)(Mge3LieREe0.4Zr alloys)are investigated to reveal the influence of homogenization treatment on microstructures and distributions of RE,Zr elements.It is found that...Mge3Lie0.4Zr alloys containing RE elements(Gd,La,Nd)(Mge3LieREe0.4Zr alloys)are investigated to reveal the influence of homogenization treatment on microstructures and distributions of RE,Zr elements.It is found that 300C24 h homogenization treatment shows better improvement on the microstructure including the refinement of grain size,the dispersion of cellular dendrite and low melting point particles.Before treatment,La and Nd segregate effectively at grain boundary and Zr segregates in the form of precipitates.Homogenization treatment induces the reduction of RE segregation.However,the segregation of Zr in precipitates cannot be abated due to the relatively low diffusion rate compared with RE elements.展开更多
研究了一种添加Ce并具有高Cu/Li的新型Al-Cu-Li-Ce合金在双极均匀化热处理过程中微观结构的演化过程,并重点探讨了该合金中t1(Al8Cu4Ce)相的形成过程及其形成机制。在凝固过程中Ag,Mg富集的粗大的T_B(Al_7Cu_4Li)相和原生的Al Cu Ce相...研究了一种添加Ce并具有高Cu/Li的新型Al-Cu-Li-Ce合金在双极均匀化热处理过程中微观结构的演化过程,并重点探讨了该合金中t1(Al8Cu4Ce)相的形成过程及其形成机制。在凝固过程中Ag,Mg富集的粗大的T_B(Al_7Cu_4Li)相和原生的Al Cu Ce相共同形成。双极均匀化热处理后有2种类型的t1相出现。该相的形成模式包括,通过Ce不断的由Al基体向在T B相上新形核的t1相扩散并导致该粒子不断长大,以及原生的Al Cu Ce相通过不断缩水并伴随Cu,Ce向各个方向扩散,由之转变为细小弥散的t_1相。同时分析发现在合金凝固过程中产生的这种先析Al Cu Ce相,不但能够促进晶粒形核,同时能够阻止晶粒进一步长大,最终导致含铈的铸态合金晶粒得到细化。展开更多
基金This work was supported by the Major State Basic Research Development Program of China(No.2013CB632203)National Key Technology R&D Program of China(2011BAE22B03)+3 种基金(2012BAF09B01)National Natural Science Foundation of China(51074207)Chinese Postdoctoral Science Foundation(2012M520634)the Fundamental Research Foundation of Central Universities(Grant Nos.N120509002 and N120309003).
文摘Mge3Lie0.4Zr alloys containing RE elements(Gd,La,Nd)(Mge3LieREe0.4Zr alloys)are investigated to reveal the influence of homogenization treatment on microstructures and distributions of RE,Zr elements.It is found that 300C24 h homogenization treatment shows better improvement on the microstructure including the refinement of grain size,the dispersion of cellular dendrite and low melting point particles.Before treatment,La and Nd segregate effectively at grain boundary and Zr segregates in the form of precipitates.Homogenization treatment induces the reduction of RE segregation.However,the segregation of Zr in precipitates cannot be abated due to the relatively low diffusion rate compared with RE elements.
基金Research Foundation of the General Armament Department(6140506)Foundation for Sci&Tech Development Project of Shandong(2014GGX102006)
文摘研究了一种添加Ce并具有高Cu/Li的新型Al-Cu-Li-Ce合金在双极均匀化热处理过程中微观结构的演化过程,并重点探讨了该合金中t1(Al8Cu4Ce)相的形成过程及其形成机制。在凝固过程中Ag,Mg富集的粗大的T_B(Al_7Cu_4Li)相和原生的Al Cu Ce相共同形成。双极均匀化热处理后有2种类型的t1相出现。该相的形成模式包括,通过Ce不断的由Al基体向在T B相上新形核的t1相扩散并导致该粒子不断长大,以及原生的Al Cu Ce相通过不断缩水并伴随Cu,Ce向各个方向扩散,由之转变为细小弥散的t_1相。同时分析发现在合金凝固过程中产生的这种先析Al Cu Ce相,不但能够促进晶粒形核,同时能够阻止晶粒进一步长大,最终导致含铈的铸态合金晶粒得到细化。