Combustion Synthesis of (Ti,V)2AlC Solid Solutions

2014 ◽  
Vol 909 ◽  
pp. 19-23
Author(s):  
Chun Liang Yeh ◽  
Wen Jung Yang
Keyword(s):  
High Temperature ◽  
Solid Solutions ◽  
Reaction Front ◽  
Combustion Temperature ◽  
Product Formation ◽  
Front Velocity ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Substitution Site ◽  
High Temperature Synthesis

(Ti,V)2AlC solid solutions with Al2O3 addition were produced by solid state combustion involving aluminothermic reduction in the mode of self-propagating high-temperature synthesis (SHS). Starting materials included Ti/V2O5/Al/Al4C3 and TiO2/V2O5/Al/Al4C3 powder mixtures. Attempts were made to obtain (Ti1-xVx)2AlC with a broad substitution percentage. Combustion exothermicity was increased by increasing V2O5 for the yield of a higher proportion of V at the substitution site, which not only increased the combustion temperature and reaction front velocity, but also facilitated the evolution of (Ti,V)2AlC. The Ti-containing samples showed higher reaction exothermicity and better product formation than those adopting TiO2. As a result, (Ti1-xVx)2AlC with x from 0.2 to 0.8 was produced from the samples composed of the Ti/V2O5/Al/Al4C3 mixture. The (Ti,V)2AlC/Al2O3 composites synthesized in this study exhibited a laminated microstructure with closely-stacked (Ti,V)2AlC slabs of about 0.30.8 μm.

Synthesis of Nanostructure MoSi2 Powder by Mechanically Assisted Self-Propagating High-Temperature Synthesis

2010 ◽  
Author(s):  
R. Meshkizadeh ◽  
H. Abdollahpour ◽  
A. Honarbakhsh-Raouf
Keyword(s):  
High Temperature ◽  
Ball Milling ◽  
Powder Mixture ◽  
Combustion Temperature ◽  
Combustion Method ◽  
Temperature Synthesis ◽  
Mixed Powder ◽  
Powder Mixtures ◽  
High Temperature Synthesis

Nanostructured MoSi2 powder has been successfully synthesized by Ball milling of Mo and Si powder mixtures and subsequent self-propagating high-temperature synthesis (SHS) process. It was observed that in comparison with the normally mixed powder, it could be easily ignited and higher combustion temperature was achieved. Based on XRD and SEM, it was confirmed that nanostructure MoSi2 powder could be prepared through self propagating combustion method from the mechanical activated powder mixture.

Superfast Sintering of Nanocrystalline Y2O3 Ceramics

2009 ◽  
Vol 66 ◽  
pp. 100-103 ◽  
Author(s):  
Xia Zheng ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Wei Min Wang ◽  
Hao Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Heating Rate ◽  
Grain Growth ◽  
Combustion Temperature ◽  
Applied Pressure ◽  
The Self ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Chemical Furnace ◽  
Maximum Combustion Temperature

Dense nanocrystalline Y2O3 ceramics without grain growth have been successfully obtained by a new method, which is based on the self-propagating high temperature synthesis and quick pressing. A suitable self-propagating system with a maximum combustion temperature of 1350 °C and a heating rate of 1300 °C/min was chosen as a chemical furnace to supply the heat to densify nanocrystalline Y2O3. Dense samples without grain growth were obtained when the applied pressure was 120 MPa.

A time-resolved x-ray diffraction study of Ti5Si3 product formation during combustion synthesis

1997 ◽  
Vol 12 (12) ◽  
pp. 3230-3240 ◽  
Author(s):  
C. R. Kachelmyer ◽  
I. O. Khomenko ◽  
A. S. Rogachev ◽  
A. Varma
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Product Formation ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Time Resolved ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
High Temperature Synthesis ◽  
Expansion Coefficients

Time-resolved x-ray diffraction (TRXRD) was performed during Ti5Si3 synthesis by the self-propagating high-temperature synthesis mode for different Ti size fractions. It was determined that the time for product formation (ca. 15 s) was independent of Ti particle size. However, the formation of Ti5Si4 phase occurred when relatively large titanium particles were used. A simultaneous measurement of the temperature and TRXRD allowed us to attribute the shifting of XRD peaks at high temperature to thermal expansion of the Ti5Si3 product. The thermal expansion coefficients differ for different crystal planes, and their numerical values compare well with those reported previously in the literature.

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 of Aluminum Nitride and its Characterization

2004 ◽  
Vol 449-452 ◽  
pp. 213-216 ◽  
Author(s):  
Jae Ryeong Lee ◽  
Ikkyu Lee ◽  
Dong Jin Kim ◽  
Yang Kyu Ahn ◽  
Hun Saeng Chung
Keyword(s):  
High Temperature ◽  
Aluminum Nitride ◽  
Sample Size ◽  
Packing Density ◽  
Bulk Sample ◽  
Nitrogen Pressure ◽  
Front Velocity ◽  
Dilution Factor ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Aluminum nitride was synthesized by self-propagating high-temperature synthesis (SHS) with flaky aluminum powder in various conditions such as particle size, nitrogen pressure (PN 2), dilution factor f( Dil</sub), packing density, and bulk sample size. AlN content in the SHS product increases with an increase of fDil, and it eventually reaches about 95 % at fDil=0.6. Generally, reaction front velocity is significantly affected by PN2 and packing density, but not by fDil. The degree of AlN conversion reduces more or less with an increase of bulk sample size, but that could be improved by using the SHS pre-prepared product as a diluent.

Fabrication of BN-AlN-TiB2 Compound Conductive Ceramics by Self-Propagating High Temperature Synthesis and Hot Isostatic Pressing

2007 ◽  
Vol 336-338 ◽  
pp. 786-789 ◽  
Author(s):  
Li Juan Zhou ◽  
Yong Ting Zheng ◽  
Shan Yi Du
Keyword(s):  
High Temperature ◽  
Composition Dependence ◽  
Bending Strength ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Isostatic Pressing ◽  
High Temperature Synthesis ◽  
Conductive Ceramics

BN-AlN-TiB2 compound conductive ceramics from powder mixtures of BN, Al, and TiB2 was fabricated by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP). The powder mixtures were shaped by isostatic cool pressing at 5-10MPa and the combustion reaction was carried at 100-200 MPa N2 by an ignitor. XRD experiments confirmed that the reaction was complete and only AlN, BN and TiB2 were detected. Optical microscopy as well as SEM with an electron probe microanalysis was used for microstructural analysis and revealed a relatively uniform distribution of particulates. The temperature-dependence and composition-dependence of the electrical resistivity of BN-AlN-TiB2 ceramics were studied. The results showed that the optimum composition was 5-10wt% BN, 30-55wt% Al and 60-40wt% TiB2, and the products had the density of 90% of the theoretical, resistivity of 80-1000 μ⋅cm and bending strength of 100-200 MPa.

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