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Phase formation and microstructural evolution during sintering of Al-Zn-Mg-Cu alloys

Shah Mohammadi, M ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1179/003258908X344707
  3. Publisher: 2010
  4. Abstract:
  5. Al–5·6Zn, Al–5·6Zn–2·5Mg and Al–5·6Zn–2·5Mg–1·6Cu (wt-%) powder blends were compacted at 350 MPa and sintered in nitrogen at different temperatures to study microstructural evolution during sintering. Densification, dimensional changes and mechanical properties of the Al alloys were investigated. Microstructural analyses were performed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and simultaneous thermal analysis (STA) in order to determine the temperature and chemical composition of the phases formed during sintering. It was shown that various liquids and intermetallic phases including Al0·71Zn0·29 at 438°C, Al0·58Mg0·42 and Al32(Mg,Zn)49 at 450°C, Al3Mg3Zn3 at 500°C, and most probably η and S phases at 600°C were formed during the heating cycle. Magnesium was found to be the most effective alloying element on the densification and microstructural development during sintering, and eventually on the mechanical properties of the investigated systems sintered below 550°C. At higher temperatures, copper also becomes effective by the formation of a liquid phase. In the present paper, the phase formation during the sintering of the 7075 Al alloy prepared from elemental powders is addressed
  6. Keywords:
  7. Al-Zn-Mg-Cu alloy ; Microstructure ; Phase formation ; Sintering ; 7075 Al alloy ; Al alloys ; Chemical compositions ; Dimensional changes ; Elemental powders ; Energy dispersive X ray spectroscopy ; Heating cycles ; Higher temperatures ; Intermetallic phasis ; Liquid Phase ; Microstructural analysis ; Microstructural development ; Phase formations ; Powder blends ; SEM ; Simultaneous thermal analysis ; Alloying elements ; Alloys ; Cerium alloys ; Copper alloys ; Magnesium ; Mechanical properties ; Microstructural evolution ; Scanning electron microscopy ; Thermoanalysis ; X ray diffraction ; X ray diffraction analysis ; X ray spectroscopy ; Zinc ; Zinc alloys ; Aluminum
  8. Source: Powder Metallurgy ; Volume 53, Issue 1 , 2010 , Pages 62-70 ; 00325899 (ISSN)
  9. URL: http://www.tandfonline.com/doi/abs/10.1179/003258908X344707