Effect of nitrogen pressure on the combustion synthesis of titanium nitride

2000 ◽  
Vol 18 (1-6) ◽  
pp. 331-338 ◽  
Author(s):  
C. Pascal ◽  
R. M. Marin-Ayral ◽  
F. Martinez ◽  
J. C. Tedenac
Keyword(s):  
Titanium Nitride ◽  
Combustion Synthesis ◽  
Nitrogen Pressure

scholarly journals Combustion Synthesis of Aluminum Oxynitride in Loose Powder Beds

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4182
Author(s):  
Alan Wilmański ◽  
Magdalena Zarzecka-Napierała ◽  
Zbigniew Pędzich
Keyword(s):  
Combustion Synthesis ◽  
Metal Powder ◽  
Weight Ratio ◽  
Nitrogen Pressure ◽  
Alumina Powder ◽  
Metal Powders ◽  
Aluminum Oxynitride ◽  
Synthesis Conditions ◽  
Aluminum Metal ◽  
Loose Powder

This paper describes combusting loose powder beds of mixtures of aluminum metal powders and aluminum oxide powders with various grain sizes under various nitrogen pressure. The synthesis conditions required at least 20/80 weight ratio of aluminum metal powder to alumina powder in the mix to reach approximately 80 wt% of γ-AlON in the products. Finely ground fused white alumina with a mean grain size of 5 μm was sufficient to achieve results similar to very fine alumina with 0.3 μm grains. A lower nitrogen pressure of 1 MPa provided good results, allowing a less robust apparatus to be used. The salt-assisted combustion synthesis upon addition of 10 wt% of ammonium nitrite resulted in a slight increase in product yield and allowed lower aluminum metal powder content in mixes to be ignited. Increasing the charge mass five times resulted in a very similar γ-AlON yield, providing a promising technology for scaling up. Synthesis in loose powder beds could be utilized for effective production of relatively cheap and uniform AlON powder, which could be easily prepared for forming and sintering without intensive grounding and milling, which usually introduce serious contamination.

Chemically activated combustion synthesis of AlON under high nitrogen pressure

2021 ◽  
Vol 232 ◽  
pp. 111560
Author(s):  
Tigran G. Akopdzhanyan ◽  
Sergey I. Rupasov ◽  
Stepan Vorotilo
Keyword(s):  
Combustion Synthesis ◽  
Nitrogen Pressure ◽  
High Nitrogen ◽  
High Nitrogen Pressure

Combustion Synthesis of Si3N4 from Si/NH4Cl at Low Nitrogen Pressure

2008 ◽  
Vol 368-372 ◽  
pp. 1767-1770 ◽  
Author(s):  
Yi Xiang Chen ◽  
Jiang Tao Li ◽  
Zhi Ming Lin ◽  
Guang Hua Liu ◽  
S.L. Yang ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Combustion Temperature ◽  
Profile Analysis ◽  
Combustion Velocity ◽  
Nitrogen Pressure ◽  
Analysis Method ◽  
Α Phase ◽  
Steady Combustion ◽  
Combustion Wave Velocity ◽  
Low Nitrogen

Combustion synthesis (CS) of Si3N4 was accomplished by using as-milled Si/NH4Cl as reactants at low nitrogen pressure. The additive of NH4Cl decreased the combustion temperature and promoted the Si nitridation. Full nitridation of Si was achieved by burning Si in pressurized nitrogen with 10 ~ 25 wt. % NH4Cl as additives while no Si3N4 diluent added. The maximum combustion temperature (Tc), the combustion velocity (u) together with the α-Si3N4 content and mean particle size (d50) of the powder products were found to be great dependent on the NH4Cl content added in the reactants. Fine Si3N4 powder products with α-phase content up to 85 wt. % were obtained via steady combustion mode. A mathematical approach named combustion wave velocity methods for the analysis of temperature profiles in CS was proposed and the reaction kinetics was discussed. The apparent activation energy calculated according to the temperature profile analysis method is 29.7 kJ/mol, which agrees well with the corresponding low temperature nitriding combustion of Si.

ChemInform Abstract: Simultaneous Synthesis and Densification of Titanium Nitride by High Pressure Combustion Synthesis.

ChemInform ◽  
2001 ◽  
Vol 32 (9) ◽  
pp. no-no
Author(s):  
R. M. Marin-Ayral ◽  
C. Pascal ◽  
F. Martinez ◽  
J. C. Tedenac
Keyword(s):  
High Pressure ◽  
Titanium Nitride ◽  
Combustion Synthesis ◽  
Simultaneous Synthesis

Combustion synthesis of AlN with melamine as an additive

2006 ◽  
Vol 21 (3) ◽  
pp. 747-753 ◽  
Author(s):  
Gunchoo Shim ◽  
Je-Shin Park ◽  
Sung-Wook Cho
Keyword(s):  
Aluminum Nitride ◽  
Combustion Synthesis ◽  
Reaction Rates ◽  
Nitrogen Pressure ◽  
Chamber Pressure ◽  
Nitrogen Flow ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Diffraction Patterns ◽  
Nitrogen Contents

Melamine (C3H6N6) was used as an additive for synthesizing aluminum nitride by combustion synthesis. It was found that at least 0.1 M of melamine addition to 1 M of aluminum and 0.8 MPa of nitrogen pressure were necessary to initiate a stable reaction. In addition to melamine, however, use of aluminum nitride as a diluent and application of forced nitrogen flow yielded better results. Analyzing the reaction temperatures, reaction rates, nitrogen contents, x-ray diffraction patterns, and scanning electron microscopy photographs, the optimum conditions for synthesizing AlN were established: (i) reactants were 90 wt% (1 M Al + 0.1 M melamine) + 10 wt% AlN diluent, (ii) chamber pressure was 0.9 MPa, and (iii) nitrogen flow rate was 15 l/min. Under these conditions, aluminum nitride with the stoichiometric nitrogen content of 34 wt% could be obtained.

Effects of nitrogen pressure and diluent content on the morphology of gel-cast-foam-assisted combustion synthesis of elongated β-Si3N4 particles

2014 ◽  
Vol 40 (8) ◽  
pp. 12553-12560 ◽  
Author(s):  
Wei Cui ◽  
Yuan Zhu ◽  
Yiyao Ge ◽  
Feiyu Kang ◽  
Xuanyi Yuan ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Nitrogen Pressure

Effects of Technical Parameters on the Phase Composition and Microstructure of Yb α-SiAlON Prepared by Combustion Synthesis

2007 ◽  
Vol 280-283 ◽  
pp. 1237-1240 ◽  
Author(s):  
G.H. Liu ◽  
Ke Xin Chen ◽  
He Ping Zhou ◽  
Xiao Shan Ning ◽  
José Maria F. Ferreira
Keyword(s):  
Phase Transformation ◽  
Phase Composition ◽  
Combustion Synthesis ◽  
Nitrogen Pressure ◽  
Nucleation And Growth ◽  
Experimental Results ◽  
Microstructure Development ◽  
Technical Parameters

In this paper, Yb a-sialon powders with elongated grains have been prepared by combustion synthesis. The effects of diluents, nitrogen pressure, adding a-sialon seeds and NH4F on the phase transformation and microstructure development of the samples are discussed systematically. The experimental results show that the addition of diluents, proper nitrogen pressure and additive NH4F can facilitate the nitridation of Si. It was also found that the added a-sialon seeds and NH4F are beneficial to the nucleation and growth of elongated grains.

On the Progress of Combustion Synthesis of Si3N4 Ceramic: From Laboratory Research to Industrial Production

2007 ◽  
Vol 336-338 ◽  
pp. 911-915 ◽  
Author(s):  
Jiang Tao Li ◽  
Yun Yang ◽  
Hai Bo Jin
Keyword(s):  
Mechanical Activation ◽  
Combustion Synthesis ◽  
Industrial Production ◽  
Large Scale ◽  
Processing Parameters ◽  
Nitrogen Pressure ◽  
Chemical Stimulation ◽  
Ammonium Salts ◽  
Laboratory Research ◽  
The Past

The progress on the combustion synthesis of Si3N4 powders during the past decades was summarized with the emphasis on the recently developed mechano-chemically activated combustion synthesis (MACS) method. The effects of processing parameters such as the addition of diluent and ammonium salts into the green mixtures, the variation of nitrogen pressure as well as the mechanical activation treatment on the degree of Si to α-Si3N4 conversion was evaluated. The combination of mechanical activation and chemical stimulation was effective in enhancing the reactivity of Si powder reactants, which was responsible for the extension of the minimum nitrogen pressure normally required for the combustion synthesis of Si3N4. This breakthrough indicates that nitriding combustion of silicon in pressurized nitrogen could be promoted by activating the solid reactants instead of by increasing the pre-exerted nitrogen pressure. The MACS process was successfully applied to the industrial production of Si3N4 powders, the regularities for the large-scale synthesis were reported, and the as-synthesized Si3N4 powder products were systematically characterized.

Preparation of Porous Si3N4 Based Ceramics by Combustion Synthesis

2007 ◽  
Vol 336-338 ◽  
pp. 1087-1089 ◽  
Author(s):  
Wen Kui Li ◽  
Jun Huai Xiang ◽  
Bao Lin Zhang
Keyword(s):  
Combustion Synthesis ◽  
Nitrogen Pressure ◽  
Porous Si ◽  
High Nitrogen ◽  
Porous Si3n4 ◽  
High Nitrogen Pressure

This paper presents the results of combustion synthesis of porous Si3N4 based ceramics from silicon powders, with fine α-Si3N4 and BN powders as diluents, under high nitrogen pressure. The effect of addition of BN on the morphology is investigated. The results revealed that the strength decreased and the porosity increased with the addition of BN, which is strongly depended on the final morphology of the products.

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