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Title: Transmission electron microscopy study of precipitates in an artificially aged Al–12.7Si–0.7Mg alloy

An investigation of Al–12.7Si–0.7Mg alloy aged at 160 °C, 180 °C and 200 °C for 3 h was carried out in order to identify the precipitating phases. Regular transmission and high resolution electron microscopy (TEM and HREM) were employed for this purpose. The studies were focused on the dark spots and needle-shaped precipitates lying in (001){sub Al} plane. Based on the HREM observations, dark spots and needle-shaped precipitates have different characteristics. The results revealed that the ellipsoidal and needle-shaped precipitates along <100> direction of the matrix coexist in the alloy by tilting experiments at given aging condition. The ellipsoidal dark spot precipitates viewing along [001]{sub Al} is not cross-sectional image of needle-shaped precipitates along <001>{sub Al}. Needle-shaped precipitate is coherent with the matrix. The diffraction pattern associated with the ellipsoidal precipitates is consistent with β″ reported in literature. - Highlights: • Wrought Al–Si–Mg alloy has been investigated to identify the precipitating phases. • The ellipsoidal and needle-shaped precipitates coexist in wrought Al–Si–Mg alloy. • The needle-shaped and ellipsoidal precipitates exhibit different characteristics.
Authors:
 [1] ;  [1] ;  [1] ;  [2]
  1. School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China)
  2. Key Lab. for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China)
Publication Date:
OSTI Identifier:
22476170
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 107; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM COMPOUNDS; DIFFRACTION; MAGNESIUM COMPOUNDS; PRECIPITATION; RESOLUTION; SILICON COMPOUNDS; TERNARY ALLOY SYSTEMS; TRANSMISSION; TRANSMISSION ELECTRON MICROSCOPY