Effect of Reactant Particle Size on the Self-Propagating High-Temperature Synthesis Reaction Behaviors in the Ni-Ti-B4C System

2008 ◽  
Vol 40 (1) ◽  
pp. 232-239 ◽  
Author(s):  
Y.F. Yang ◽  
H.Y. Wang ◽  
R.Y. Zhao ◽  
Q.C. Jiang
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
The Self ◽  
Synthesis Reaction ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Reaction mechanism of self-propagating high-temperature synthesis reaction in the Ni–Ti–B4C system

2008 ◽  
Vol 23 (9) ◽  
pp. 2519-2527 ◽  
Author(s):  
Y.F. Yang ◽  
H.Y. Wang ◽  
R.Y. Zhao ◽  
Y.H. Liang ◽  
Q.C. Jiang
Keyword(s):  
High Temperature ◽  
Reaction Mechanism ◽  
Intermetallic Compounds ◽  
Eutectic Point ◽  
The Self ◽  
Mutual Diffusion ◽  
Synthesis Reaction ◽  
Temperature Synthesis ◽  
Early Appearance ◽  
High Temperature Synthesis

The SHS reaction in the Ni–Ti–B4C system starts with the formation of Ni–Ti and Ni–B intermetallic compounds from the solid interacted reaction among the reactants and, subsequently, the formation of Ni–Ti and Ni–B liquid at the eutectic point. Meanwhile, some C atoms from the reaction between Ni and B4C can dissolve into Ni–Ti liquid to form TiC. The heat generated from these reactions can promote the mutual diffusion of Ni–Ti–C and Ni–B liquid and simultaneously accelerate the formation of Ni–Ti–C–B liquid. Finally the precipitation of TiC and TiB2 occur when the C and B atoms in the liquid become supersaturated. The addition of Ni not only promotes the occurrence of the self-propagating high temperature synthesis (SHS) reaction by forming Ni–Ti liquid, but also accelerates the SHS reaction by forming Ni–B liquid and dissociative C. The early appearance of dissociative C from the reaction between Ni and B4C causes the formation of TiC prior to that of TiB2.

Role of Fe incorporation in the self-propagating high-temperature synthesis reaction in an Al–Ti–B4C system

2009 ◽  
Vol 24 (6) ◽  
pp. 2066-2078
Author(s):  
Ping Shen ◽  
Wenya Li ◽  
Binglin Zhou ◽  
Qichuan Jiang
Keyword(s):  
Particle Size ◽  
The Self ◽  
The Other ◽  
Synthesis Process ◽  
Synthesis Reaction ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Molten Phase ◽  
Combustion Behaviors

Effects of Fe incorporation into Al–Ti–B4C reactants on the combustion behaviors, reaction mechanism, synthesized products, and possible natural convection of fluids were investigated. The incorporation of Fe significantly promotes the self-propagating reaction and decreases the reaction dependence on the B4C particle size. The prior reaction of Fe with B4C leads to the decomposition of B4C and formation of Fe2B and free carbon. On the other hand, the reaction of Fe with Ti and Al gives rise to the emergence of Fe–Ti and Fe–Ti–Al eutectic liquids. As a result, the diffusivity and reactivity of the dissociated carbon and boron atoms are greatly facilitated and the reaction is substantially promoted, yielding a desirable product of TiC, TiB2, and FeAl phases. Moreover, the incorporation of Fe may enhance free convection of the molten phase in the reaction zone and thus contribute to the combustion synthesis process.

Initiation of SHS Flame Induced by Another SHS Flame—Evaluation of the Ignition Energy

2000 ◽  
Vol 123 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Atsushi Makino
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Physicochemical Parameters ◽  
Analytical Study ◽  
Energy Use ◽  
The Self ◽  
Ignition Energy ◽  
Temperature Synthesis ◽  
System Parameters ◽  
High Temperature Synthesis

Relevant to the self-propagating high-temperature synthesis (SHS) process, an analytical study has been made to investigate dependence of its flame initiation on system parameters, such as operating and physicochemical parameters, in order to obtain ignition energy. Use has been made of the heterogeneous theory which can satisfactorily account for the premixed mode of the bulk flame propagation supported by the nonpremixed mode of particle consumption. It is found that the ignition energy strongly depends on not only heat loss, but also particle size of the higher melting-point metal, which has not been captured in the homogeneous theory.

scholarly journals Effect of Cu addition and heat treatment self-propagating high temperature synthesis reaction in Al-Ti-C system

2008 ◽  
Vol 40 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Y.X. Li ◽  
J. Hu ◽  
Y.H. Liu ◽  
Z.X. Guo
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Combustion Temperature ◽  
The Self ◽  
Synthesis Reaction ◽  
Reaction Products ◽  
Temperature Synthesis ◽  
Rigid Framework ◽  
High Temperature Synthesis ◽  
Al2cu Phase

Effect of Cu addition and heat treatment on the self-propagating high temperature synthesis reaction have been investigated. The results show that Cu reacts with Al to form Al2Cu phase. With the addition of Cu, the combustion temperature of the system decreases and the porosity of the products is reduced, the size of TiC particulate decreases in the SHS reaction products. Specially, when heat treatment is carried out for the sintering products at 800 ?C, the rigid framework (sintering neck) between TiC particles was formed.

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