Microstructural Characterization and Phase Diagram Calculation of a Less Known Al–Fe–Mn–Si Phase in a SiCp/2014Al Composite. (August 2019)

• Record Type: Journal Article
• Authors: Hu, Ying; Ouyang, Qiubao; Zhao, Bingbing; Zhang, Lanting
• Is Part Of: Microscopy and microanalysis. Volume 25:Number 4(2019)
• Page Start: 859
• Page End: 865
• Publication Date: 2019-08
• Subjects: Al–Fe/Mg–Si alloys, -- crystal structure, -- intermetallic alloys and compounds, -- metal matrix composites, -- SiCp/Al composites; Microscopy -- Periodicals; Microchemistry -- Periodicals; 502.82
• DOI: 10.1017/S1431927619000618
• Languages: English
• ISSNs: 1431-9276

Abstract

Abstract: A systematic characterization of a less known Al, Fe, Mn, and Si phase in a SiC particulate-reinforced 2014Al composite (SiC p /2014Al) was performed. In addition to the expected CuAl2 phase, the Al, Fe, Mn, and Si phase was formed as either an adhesion (>1 µ m) onto SiC in the as-cast composite, or as a precipitate (<100 nm) in the matrix after hot extrusion. The structure of the phase was identified as cubic by both X-ray diffraction and selected area electron diffraction (SAED). The SAED pattern also indicated that the structure belongs to the Pm $\bar{3}$ space group instead of Im $\bar{3}$ . The thermodynamic phase diagram was calculated, confirming the presence of an α -AlFeMn or α -AlFeSi phase in the Al–Fe–Mn and Al–Fe–Si ternary systems, respectively, within the Fe, Mn, and Si content range corresponding to 2014Al. Wavelength-dispersive spectroscopy analysis indicated that the composition of the phase is close to Al12 (Fe, Mn)3 Si2, in which the Mn/Fe ratio is in the range of 0.6–1.4. The determined Mn/Fe ratio corresponds to the nominal composition of Mn and Fe in the alloy.