Induction-field-activated self-propagating high-temperature synthesis of AlN–SiC solid solutions in the Si3N4–Al–C system

2000 ◽  
Vol 15 (11) ◽  
pp. 2514-2525 ◽  
Author(s):  
D. Kata ◽  
M. Ohyanagi ◽  
Z. A. Munir
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Solid Solutions ◽  
Microstructural Analysis ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Induction Field ◽  
High Temperature Synthesis ◽  
Isostatic Compaction ◽  
Reaction Routes

The synthesis of AlN–SiC solid solutions from Si3N4, Al, and C was investigated using the induction-field-activated/self-propagating high-temperature synthesis/static pseudo-isostatic compaction technique. Careful x-ray diffraction analyses were made on the products of combustion to determine reaction routes. Optical microscopy as well as scanning electron microscopy with an electron probe microanalysis was used for microstructural analysis. It was found that initially molten aluminum reacted with silicon nitride producing an Al–Si alloy. At higher temperatures, aluminum evaporated from the Al–Si liquid and the synthesis of AlN via a vapor phase process took place. Subsequently, dissolution of AlN into molten Si resulted in the formation of an AlN–SiC solid solution from the Al–N–Si–C liquid phase. However, below 1850 °C, the resulting solid solution of 4AlN–3SiC was not fully crystallized. Combustion temperatures above or equal to 1850 °C were required to prepare a highly crystallized solid solution with a morphology exhibiting hexagonal platelets. Based on these observations, a model for the formation of AlN–SiC solid solution is proposed.

Self-propagating high-temperature synthesis microalloying of MoSi2 with Nb and V

2003 ◽  
Vol 18 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
F. Maglia ◽  
C. Milanese ◽  
U. Anselmi-Tamburini ◽  
Z. A. Munir
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Tetragonal Phase ◽  
Synthesis Method ◽  
The Self ◽  
Alloying Elements ◽  
Alloying Element ◽  
Temperature Synthesis ◽  
Starting Mixture ◽  
High Temperature Synthesis

Microalloying of MoSi2 to form Mo(1−x)MexSi2 (Me = Nb or V) was investigated by the self-propagating high-temperature synthesis method. With alloying element contents up to 5 at.%, a homogeneous C11b solid solution was obtained. For higher contents of alloying elements, the product contained both the C11b and the hexagonal C40 phases. The relative amount of the C40 phase increases with an increase in the content of alloying metals in the starting mixture. The alloying element content in the hexagonal C40 Mo(1−x)MexSi2 phase was nearly constant at a level of about 12 at.% for all starting compositions. In contrast, the content of the alloying elements in the tetragonal phase is considerably lower (around 4 at.%) and increases slightly as the Me content in the starting mixture is increased.

Preparation and Microwave Permittivity of SiC-AlN Solid Solution Powders

2007 ◽  
Vol 336-338 ◽  
pp. 310-312
Author(s):  
Xiao Kui Liu ◽  
Wan Cheng Zhou ◽  
Fa Luo ◽  
Dong Mei Zhu
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Carbon Black ◽  
Atomic Ratio ◽  
Nitrogen Atmosphere ◽  
Argon Atmosphere ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Microwave Permittivity ◽  
Shs Method

SiC-AlN solid solution powders were prepared from the mixtures of aluminum, silicon and carbon black in a nitrogen atmosphere with preheating self-propagating high temperature synthesis (SHS) method. The powders synthesized with different ratios of Al/Si were mixed with paraffin wax and the microwave permittivity of the mixtures was measured at the frequency of 8.2~12.4GHz. The results were contrasted with that of SiC powders synthesized by preheating SHS in argon and nitrogen atmosphere respectively. The ε′, ε″, and the tgδ (ε″/ε′) of the mixture of SiC prepared in a nitrogen atmosphere are highest, followed with those of the SiC-AlN solid solution powders and the SiC powders prepared in an argon atmosphere. Along with the increase of atomic ratio of Al/Si, the ε′, ε″, and tgδ of SiC-AlN solid solution decrease. We believe that, with the increase of AlN dissolved, the concentration of carriers and the effect of dielectric relaxation will decrease because of the two contrary dopants.

A Study of Fe-Based Composite Coating Fabricated by the Self-Propagating High Temperature Synthesis

2012 ◽  
Vol 626 ◽  
pp. 138-142
Author(s):  
Saowanee Singsarothai ◽  
Vishnu Rachpech ◽  
Sutham Niyomwas
Keyword(s):  
High Temperature ◽  
Composite Coating ◽  
Steel Substrate ◽  
The Self ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Precursor Powders ◽  
Scanning Electron

The steel substrate was coated by Fe-based composite using self-propagating high-temperature synthesis (SHS) reaction of reactant coating paste. The green paste was prepared by mixing precursor powders of Al, Fe2O3and Al2O3. It was coated on the steel substrate before igniting by oxy-acetylene flame. The effect of coating paste thickness and the additives on the resulted Fe-based composite coating was studied. The composite coating was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) couple with dispersive X-ray (EDS).

Optimization of Rare Earth Dope on MAl2O4 (M = Ba, Sr) by Self-Propagating High Temperature Synthesis

2012 ◽  
Vol 488-489 ◽  
pp. 442-446 ◽  
Author(s):  
Taschaporn Sathaporn ◽  
Sutham Niyomwas
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Broad Band ◽  
Emission Spectra ◽  
Rare Earth Ions ◽  
Ocean Optics ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Microscope Technique

The Eu2+ doped barium aluminate (BaAl2O4:Eu2+) and strontium aluminate (SrAl2O4:Eu2+) with high brightness were synthesized by self-propagating high temperature synthesis (SHS) method. The influence of doping rare earth ions (Eu2+) on the luminescence of MAl2O4:Eu2+ were described in this study. The reactions were carried out in a SHS reactor under static argon gas at a pressure of 0.5 MPa. The morphologies and the phase structures of the products have been characterized by X-ray diffraction (XRD) and scanning electron microscope technique (SEM). The emission spectra of the products have been measured by an Ocean optics spectrometer at room temperature. Broad band UV excited luminescence was observed for BaAl2O4:Eu2+ and SrAl2O4:Eu2+ in the green region peak at λmax = 501 nm and 523 nm, respectively. The optimum Eu2+ doping ratio were 10.5 mol% and 6 mol% for BaAl2O4:Eu2+ and SrAl2O4:Eu2+, respectively

Self-Propagating High-Temperature Synthesis of Fe-W(B, C) Based Composite

2013 ◽  
Vol 748 ◽  
pp. 46-50 ◽  
Author(s):  
Saowanee Singsarothai ◽  
Sutham Niyomwas
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
The Self ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Flame Ignition ◽  
Scanning Electron

Fe-W based composite have successfully been prepared using natural resource. The ferberite (Fe (Mn, Sn)WO4) tailings mixed with aluminum, carbon and boron oxide powder were used as reactants. The reactants were pressed and followed by oxy-acetylene flame ignition. The products from the self-propagating high-temperature synthesis (SHS) reaction were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) couple with dispersive X-ray (EDS).

Microstructure and Wear Performance of Cu-Mo-Si Alloys Fabricated by Self-Propagation High-Temperature Synthesis

2010 ◽  
Vol 658 ◽  
pp. 408-411
Author(s):  
Hui Xie ◽  
Lei Jia ◽  
Si Ming Wang ◽  
Ji Ling Zhu ◽  
Zhen Lin Lu
Keyword(s):  
High Temperature ◽  
Wear Behavior ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Wear Performance ◽  
X Ray ◽  
Cu Content ◽  
High Temperature Synthesis ◽  
Pin On Disc ◽  
Worn Surface

Cu-Mo-Si alloys with different Cu contents were prepared by self-propagation high-temperature synthesis (SHS). The microstructure and the worn surface morphology were observed using scanning electron microscopy (SEM) together with energy dispersive X-ray spectroscopy (EDS) analysis. Phase composition was determined by X-ray diffraction (XRD). The wear behavior of the Cu-Mo-Si alloys was characterized by pin-on-disc wear tester. The results showed that most of Si atoms dissolved in Cu matrix or resulted in formation of compound with Cu, while only small amount of Si atoms reacted with Mo atoms to form Mo5Si3 particles in the Cu-Ni-Si alloys with 80% Cu content. The wear rate of Cu-Mo-Si alloys descended with a decrease of Cu content, and the predominant wear mechanism could be identified as abrasive wear for Cu content less than 90% and plastic deformation for Cu content higher than 90%.

Synthesis of WSi2-W5Si3 Intermetallic Alloy via Self-Propagating High Temperature Synthesis

2018 ◽  
Vol 280 ◽  
pp. 121-126
Author(s):  
Si Thu Myint Maung ◽  
Tawat Chanadee ◽  
Sutham Niyomwas
Keyword(s):  
High Temperature ◽  
Energy Minimization ◽  
Standard Gibbs Energy ◽  
Equilibrium Composition ◽  
Intermetallic Alloy ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Minimization Method ◽  
X Ray ◽  
High Temperature Synthesis

Intermetallic alloy of tungsten silicide (WSi2-W5Si3) was synthesized by self-propagating high temperature synthesis (SHS) from the reactant of tungsten oxide (WO3) and silicon lump (Si) using magnesium (Mg) as fuel. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the possible reacting species. The as-SHS products were characterized by X-ray diffraction (XRD) technique. The magnesiothermic reaction process successfully synthesized dense of WSi2-W5Si3intermetallic alloy. According to the experimental results, it can be proposed that the reaction also promotes the phase separation between alloy and oxide slag of the product.

Sign in / Sign up

Export Citation Format

Share Document