L12型Al3（Yb,Zr）相结构的第一性原理计算和实验研究  

First-principles calculations study and experimental results of L12-structured Al3（Yb,Zr） precipitate

作　　者：陈卓 方华婵[1] 祝昌军[1] 朱佳敏 CHEN Zhuo;FANG Huachan;ZHU Changjun;ZHU Jiamin(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室

出　　处：《粉末冶金材料科学与工程》2020年第1期1-10,共10页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金青年基金资助项目(51501228);湖南省自然科学基金资助项目(2015JJ3167);中南大学研究生科研创新项目(1053320183017)

摘　　要：采用基于密度泛函理论的第一性原理平面波赝势从头算量子力学方法,对L12结构的Al3Zr,Al3Sc,Al3Yb,以及Zr替代部分Sc或Yb的Al3(Sc0.5,Zr0.5)和Al3(Yb0.5,Zr0.5)化合物的晶格常数和形成焓进行计算。计算结果表明,L12结构Al3(Yb0.5,Zr0.5)化合物是热力学稳定的,在铝中易以共格态形式析出。通过透射电镜观察发现,Al-Zr-Yb合金经热处理后析出大量尺寸为20~80 nm的L12结构Al3(Yb,Zr)弥散相,芯部富Zr的Al3(Yb,Zr)和芯部富Yb的Al3(Yb,Zr)相均为明显的壳核结构。L12结构Al3(Yb,Zr)相的高温析出硬化作用及稳定性和抑制再结晶效果均优于L12结构Al3Zr相。The formation energy and lattice constant of L12-structured Al3Zr,Al3Sc,Al3Yb,Al3(Sc0.5,Zr0.5),Al3(Yb0.5,Zr0.5)compounds were calculated from first-principles based on plane-wave pseudopotential method.The calculated results indicate that the L12-structured Al3(Yb0.5,Zr0.5)phase is thermodynamically stable and easy to precipitate coherently in Al matrix.With the results of TEM,high-density of coherent,L12-structured Al3(Yb,Zr)precipitates with 20−80 nm are precipitated in as-homogenized Al-Zr-Yb alloy,among them,core Zr-riched Al3(Yb,Zr)and core Yb-riched Al3(Yb,Zr)phases have obvious shell-core structure.Uniform and high density precipitation of L12-structured Al3(Yb,Zr)causes an improvement of precipitation-hardened effect and inhibit-recrystallization ability,compared to L12-structured Al3Zr precipitates in pure aluminum.

关 键 词：Al-Zr-Yb合金 第一性原理 Al3(Yb Zr) 沉淀相 再结晶 

分 类 号：TG146.4[一般工业技术—材料科学与工程]