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Synthesis and characterization of Al2O3-SiC nano composite by sol-gel method and the effect of tio2 on sintering

Rezaie, H. R ; Sharif University of Technology | 2011

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  1. Type of Document: Article
  2. DOI: 10.4028/www.scientific.net/JNanoR.13.7
  3. Publisher: 2011
  4. Abstract:
  5. In the present article, α-Al2O3 nano powder was synthesized by a simple aqueous sol-gel method by using AlCl3 as precursor. It was shown that the gel calcined at 1000°C, 1100 °Cand 1200 °Cresulted in the formation of a crystalline ?-Al2O3 nano powder. In continue TEOS and saccharose was used to prepare SiO2 xerogels containing carbon nano particles. The conversion of the gel to β-SiC nano powders was accomplished by carbothermal reduction at 1500°Cfor 1 h in argon atmosphere. In second pace alumina matrix composites with nano particles of 5 vol% SiC were prepared with the addition of TiO 2 as sintering aid and densified by pressureless sintering method at 1600°Cand 1630°C for 2 h in nitrogen atmosphere. Green pellets were obtained by uniaxial pressing of 137 MPa. Maximum density (97.3%) was achieved at 1630°C. Vickers hardness was 16.5 GPa after sintering at 1630°C. Scanning electron microscopy revealed that the SiC particles were well distributed throughout the composite matrix. The precursors and the resultant powders were characterized by X-ray diffraction (XRD), thermal analysis (STA) and scanning electron microscopy (SEM)
  6. Keywords:
  7. Al2O3 ; TiO2 ; Al2O3 ; Alumina matrix composites ; Argon atmospheres ; Carbon nano particles ; Composite matrices ; Green pellets ; Maximum density ; Nano powders ; Nitrogen atmospheres ; Pressureless sintering ; SEM ; Sic ; SiC particles ; Sintering Aid ; Sol-gel methods ; Thermal analysis ; TiO ; Uni-axial pressing ; Aluminum ; Calcination ; Carbothermal reduction ; Gels ; Laser applications ; Nanocomposites ; Nanoparticles ; Powders ; Scanning electron microscopy ; Silicon carbide ; Sol-gel process ; Sol-gels ; Sols ; Sugar (sucrose) ; Vickers hardness ; X ray diffraction ; X ray powder diffraction ; Sintering
  8. Source: Journal of Nano Research ; Volume 13 , 2011 , Pages 7-19 ; 16625250 (ISSN)
  9. URL: http://www.scientific.net/JNanoR.13.7