Reaction mechanism and mechanical properties of an aluminum-based composite fabricated in-situ from Al-SiO2 system

Zhu, Heguo, Dong, Kang, Huang, Jiewen, Li, Jianliang, Wang, Gui and Xie, Zonghan (2014) Reaction mechanism and mechanical properties of an aluminum-based composite fabricated in-situ from Al-SiO2 system. Materials Chemistry and Physics, 145 3: 334-341. doi:10.1016/j.matchemphys.2014.02.020


Author Zhu, Heguo
Dong, Kang
Huang, Jiewen
Li, Jianliang
Wang, Gui
Xie, Zonghan
Title Reaction mechanism and mechanical properties of an aluminum-based composite fabricated in-situ from Al-SiO2 system
Formatted title
Reaction mechanism and mechanical properties of an aluminum-based composite fabricated in-situ from Al-SiO2 system
Journal name Materials Chemistry and Physics   Check publisher's open access policy
ISSN 0254-0584
1879-3312
Publication date 2014-06-16
Year available 2014
Sub-type Article (original research)
DOI 10.1016/j.matchemphys.2014.02.020
Open Access Status
Volume 145
Issue 3
Start page 334
End page 341
Total pages 8
Place of publication Lausanne, Switzerland
Publisher Elsevier
Collection year 2015
Language eng
Formatted abstract
An (α-Al2O3 + Si)/Al composite was fabricated by an in situ process called exothermic dispersive synthesis from a powder blend of Al and SiO2. The synthesis mechanism and resulting microstructure of the composite were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray energy dispersive spectroscopy (EDS). It was found that when the reinforcement volume fraction was 30%, Al reacted with SiO2 at a temperature of around 950 K to form α-Al2O3 and Si, and the corresponding apparent activation energy was 235 kJ mol-1. The apparent activation energy of the reaction decreases with the increase of the reinforcement volume fraction. On the other hand, with increasing heating rate, the reaction time was reduced and the characteristic exothermic peak shifted to a higher temperature. The tensile strength and elongation of the composite having the reinforcement volume fraction of 30% were 165 MPa and 3.95%, respectively. On the tensile fracture surfaces, there were many fine dimples in addition to some fractured blocks. The α-Al2O3 particles were located in the center of the fine dimples. The Si crystal blocks fractured along certain cleavage plane in a brittle manner and are a limiting factor to the tensile property of the newly-developed composite. Therefore, the elimination or replacement of the Si crystals by a tougher phase is an important consideration for future work.
Keyword Composite materials
Chemical synthesis
Differential scanning calorimetry (DSC)
Mechanical properties
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mechanical & Mining Engineering Publications
Official 2015 Collection
 
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