文章信息/Info

Title:

Application and Progress of Quantitative Micro- and Nano- structure Characterization for Materials Design of Al alloys

作者:

李凱1; 2; 杜勇1; 2; 趙丕植3; 金展鵬4

(1. 中南大學 粉末冶金國家重點實驗室，湖南省 長沙市 410083 中國；
2. 中南大學 中德鋁合金微結構聯合實驗室，湖南省 長沙市 410083 中國；
3.中鋁科學技術研究院有限公司，北京市102209 中國；
4. 中南大學 材料科學與工程學院，湖南省 長沙市 410083 中國)

Author(s):

LI Kai1; 2;  DU Yong1; 2;  ZHAO Pizhi3;  JIN Zhanpeng4

 (1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Sino-German Cooperation Group “Microstructure in Al alloys”, Central South University, Changsha 410083, China;
3. CHINALCO Research Institute of Science and Technology, Beijing 102209, China;
 4. School of Materials Science and Engineering, Central South University, Changsha 410083, China)

關鍵詞:

析出相; 晶體結構; 體積分數; 電子衍射; 低電壓; 低劑量; 原位加熱

Keywords:

 ; Precipitate;  Crystal structure;  Volume fraction;  Electron diffraction;  Low voltage;  Low dose;  in-situ heating

DOI:

10.7502/j.issn.1674-3962.2017.06.02

文獻標志碼:

A

摘要:

材料基因工程是鋁合金實現高效設計的必經途徑，而定量結構表征是鋁合金設計和制造知識系統中關于微結構模擬及其控制的不可或缺的輸入及驗證。對鋁合金而言，定量的微納尺度結構表征包括精準的物相晶體結構鑒定、成分測定等，以及在此基礎上進行的物相尺寸、數密度及體積分數等關鍵結構參數的精準測量。本文以Al-Mg-Si(-Cu)合金為例，綜述了系列表征技術在鋁合金微納結構定量表征中的應用。首先，指出高分辨透射電子顯微術、高角環形暗場及環形明場掃描透射電子顯微術等技術對研究鋁合金中常見的納米析出相的原子尺度結構有明顯的優勢，但是也存在電子束損傷高的風險；三維原子探針尤其適合對原子團簇及納米析出相進行精準的成分測定，但也存在樣品小、破壞性檢測、無法達到原子分辨率的問題；而選區電子衍射等傳統技術則正好與之互補，同時低電壓、低劑量率的高分辨TEM觀察也是未來值得努力的方向之一。在另一方面，介紹了最近發展起來的一種主要基于傳統的會聚束電子衍射來測量納米析出相體積分數的精準易行的方法。最后指出在未來研究中，結合前述納米至原子尺度結構表征手段以及聚焦離子束連續切片法、電子全息照相術、X射線納米全息照相術等微米-納米之間尺度的表征手段對鋁合金實現多過程、跨尺度定量結構表征的意義，并指出基于原位加熱TEM觀察來實現動態結構表征是未來的重要發展方向之一。

Abstract:

Materials Genome Initiative is one of the routes towards high-efficiency design of aluminum alloys, to which quantitative structure characterization is the indispensable input and verification. As in the case for Al alloys, the quantitative micro- and nano- structure characterization includes the accurate and high-precision determination of not only crystal structures and the corresponding compositions, but also that of key structure parameters such as the sizes, number densities and volume fractions of phases. This paper takes the example of Al-Mg-Si(-Cu) alloy and summarizes the applications of various techniques to quantitative micro- and nano- structure characterization in Al alloys. Firstly, it is pointed out that advanced techniques such as high-resolution transmission electron microscopy, high angle annular dark firld and annular bright field scanning transmission electron microscopy show apparent advantages in investigating the atomic scale structure of nano-precipitates in Al alloys, meanwhile they display the high risk of electron beam damage; 3-dimensional atom probe fits very well the demands for accurate and precise compositional determination of atomic clusters and nano-precipitates but is destructive and is restricted by the small specimen volume and the quasi-nano spatial resolution; selected area electron diffraction is complementary to them, and more attention should be paid to the low-voltage low-dose high resolution TEM study. On the other hand, most recently an accurate, precise and facile method has been established for the determination of precipitate volume fraction based on convergent beam electron diffraction. Lastly, it has been predicted that the coupling of the above mentioned nano- to atomic- scale structure characterization techniques with the micro- to nano- scale characterization techniques such as focused ion beam serial sectioning, electron tomography and X-ray nano-tomography in the multi-procedure multi-scale quantitative structure characterization of Al alloys, as well as the incorporation of dynamic structure characterization by in-situ heating TEM observation, are possible trends in future Al alloy studies.