急冷Al-Cu-Cr合金中二十面体准晶-晶体相变的原位TEM研究  

In-situ TEM investigation on icosahedral quasicrystal-to-crystal transformations in rapidly solidified Al-Cu-Cr alloy

作　　者：王瑞萍[1] 孙威[1] 周玲玲[1] 

机构地区：[1]北京工业大学固体微结构与性能研究所,北京100124

出　　处：《电子显微学报》2015年第5期395-400,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.11274027);北京市自然科学基金资助项目(No.2132019)

摘　　要：利用透射电子显微镜原位加热技术研究了快速凝固Al70Cu10Cr20合金中富Cr二十面体准晶的相变过程。结果表明,当加热温度达到700℃时,亚稳Al-Cu-Cr二十面体准晶相转变为具有体心立方结构的γ1相,其晶格常数为a=0.91 nm。二十面体准晶相到γ1相的转变为扩散型相变、伴随着长程准周期序的破坏和原子团的瓦解。γ1相的形成经历了形核与晶粒长大阶段,其生长主要受Al原子和Cu原子的扩散控制。The phase transformation process of the Cr-rich metastable icosahedral quasicrystal phase （ I-phase ） during heating the rapidly-solidified Al70 Cu10 Cr20 alloy were investigated by means of in-situ TEM technique. It was observed that, when the heating temperature reached 700 ℃, the Cr-rich metastable I-phase transformed into the crystalline γ1-phase with a bcc structure and lattice constant of 0.91 nm. The I-to-γ1 phase transformation is a diffusion-controlled process including nucleation and grain growth of theγ1-phase, along with degradation of long-range quasiperiodic order and disintegration of the atomic clusters in the I-phase. The growth of the γ1-phase is mainly dominated by the diffusion of Al and Cu atoms.

关 键 词：Al-Cu-Cr 亚稳二十面体准晶 相变 TEM原位加热 

分 类 号：O76[理学—晶体学]