Back to Search
Start Over
In-situ synthesis, microstructure and mechanism of SiC/Al–Mg–Si composites: Effects of Mg addition
- Source :
- Ceramics International. 46:17675-17683
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- The SiC/Al–Mg–Si composite was obtained by in-situ synthesis, and the effects of Mg addition were investigated in this process. Mechanism of in situ SiC growth in the Resin–Al–Mg–Si system was investigated by fabricating and characterizing a SiC/Al–Mg–Si composite under moderate conditions. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to analyze the phase and its microstructure, with the aim of investigating the evolvement of grains in the alloy matrix. Mg2Si formed under higher Mg added conditions, which decreased the molten liquid and Si solute concentrations. Tiny amounts of MgO and MgAl2O4 proved that the pyrolysis gas of resin reacts slightly with the matrix. The key conditions of in-situ synthesis SiC were found that the Mg addition and the Si concentration in the molten alloy were 3%–5% and over 17. 27 % respectively. Ostwald ripening was used to explain the decrease in tiny SiC grains at elevated temperatures. In situ SiC growth is controlled by the interfacial reaction-diffusion mixed model through two different routes in the molten alloy. Two modes of in-situ synthesis were suggested. The intermediate product and template for in situ SiC growth are Al4C3, and Si was shown to diffuse into its particles gradually. Flowing Si in molten alloy reacted with pyrolysis C directly. Specimens validated the peak bending strength with a rise in temperature. The maximal bending strength was 251.89 MPa.
- Subjects :
- 010302 applied physics
Ostwald ripening
Materials science
Scanning electron microscope
Process Chemistry and Technology
Composite number
Alloy
02 engineering and technology
engineering.material
021001 nanoscience & nanotechnology
Microstructure
01 natural sciences
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
symbols.namesake
Transmission electron microscopy
Phase (matter)
0103 physical sciences
Materials Chemistry
Ceramics and Composites
engineering
symbols
Composite material
0210 nano-technology
Pyrolysis
Subjects
Details
- ISSN :
- 02728842
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- Ceramics International
- Accession number :
- edsair.doi...........69b08df5a71c67a4f57c64f799e30418