Self-Propagating High-Temperature Synthesis of TiB2-Ti(C, N) Cermets Composite Powder

2012 ◽  
Vol 468-471 ◽  
pp. 1247-1250 ◽  
Author(s):  
Fang Yang ◽  
Zhi Meng Guo ◽  
Jun Jie Hao ◽  
Yong Liang Shi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Ni Addition ◽  
Brittle Phase

The ultra-fine TiB2-Ti(C, N) composite powders were prepared by self-propagating high-temperature synthesis (SHS) with Ti, BN and C powders as its starting materials. The morphology of the products was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed the composite powders were consisted of the mainly phases Ti(C, N), TiB2 and a small amount of TiN phase. With the Ni addition, the brittle phase Ni3B was appeared. SEM results revealed that the composite powders had a uniform particle size, a round grain-shaped structure and a narrow size distribution and the average particle size of which is less than 1μm.

Self-Propagating High-Temperature Synthesis of Carbide- and Boride-Aluminides

2006 ◽  
Vol 45 ◽  
pp. 1024-1028 ◽  
Author(s):  
Kiyotaka Matsuura ◽  
Yusuke Hikichi ◽  
Yuki Obara
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Average Particle Size ◽  
Average Particle ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
High Temperature Synthesis ◽  
Tic Particle ◽  
Tib2 Particles

TiC- and TiB2-FeAl composites have been produced using the Self-propagating High-temperature Synthesis (SHS) method under Pseudo Hot Isostatic Pressing (PHIP). When mixtures of the elemental powders were heated to a temperature near the melting point of Al under a PHIP of 150 MPa, the powder mixtures exothermically reacted and produced TiC particle dispersed and TiBB2 particle dispersed FeAl-matrix composites. As the volume factions of TiC and TiB2 particles increased from 0.3 to 0.8, the average particle size increased from approximately 1 to 10 μm and the average Vickers hardness increased from approximately 600 to 1600 in both the TiC-FeAl and TiB2-FeAl systems. The application of the PHIP remarkably reduced the porosity of the SHS products. Preheating of the elemental powder mixtures at 773 K for 30 minutes also reduced the porosity. Moreover, the preheating reduced the particle size in the SHS products. It was suggested that degassing of the powder surfaces and mutual diffusion between the different powders should have occurred during the preheating, which led to reduction in pore formation and reduction in heat generation at the SHS reactions, respectively.

scholarly journals High-Temperature Synthesis of Metal–Matrix Composites (Ni-Ti)-TiB2

2021 ◽  
Vol 11 (5) ◽  
pp. 2426
Author(s):  
Vladimir Promakhov ◽  
Alexey Matveev ◽  
Nikita Schulz ◽  
Mikhail Grigoriev ◽  
Andrey Olisov ◽  
...  
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Average Particle Size ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Currently, metal–matrix composite materials are some of the most promising types of materials, and they combine the advantages of a metal matrix and reinforcing particles/fibres. Within the framework of this article, the high-temperature synthesis of metal–matrix composite materials based on the (Ni-Ti)-TiB2 system was studied. The selected approaches make it possible to obtain composite materials of various compositions without contamination and with a high degree of energy efficiency during production processes. Combustion processes in the samples of a 63.5 wt.% NiB + 36.5 wt.% Ti mixture and the phase composition and structure of the synthesis products were researched. It has been established that the synthesis process in the samples proceeds via the spin combustion mechanism. It has been shown that self-propagating high-temperature synthesis (SHS) powder particles have a composite structure and consist of a Ni-Ti matrix and TiB2 reinforcement inclusions that are uniformly distributed inside it. The inclusion size lies in the range between 0.1 and 4 µm, and the average particle size is 0.57 µm. The obtained metal-matrix composite materials can be used in additive manufacturing technologies as ligatures for heat-resistant alloys, as well as for the synthesis of composites using traditional methods of powder metallurgy.

Properties of Copper and Molybdenum Sulfide Powders Produced by Self-Propagating High-Temperature Synthesis

2013 ◽  
Vol 872 ◽  
pp. 191-196 ◽  
Author(s):  
Farabi Bozheyev ◽  
Vladimir V. An ◽  
Yuriy Irtegov
Keyword(s):  
High Temperature ◽  
Molybdenum Disulfide ◽  
Copper Sulfide ◽  
Average Particle Size ◽  
Electrical Explosion ◽  
Molybdenum Sulfide ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Electrical Explosion Of Wires

Copper and molybdenum sulfide nanopowders were prepared by self-propagating high-temperature synthesis in argon. The initial copper powder and molybdenum powder were produced by electric spark dispersion in hexane and by electrical explosion of wires (EEW) in argon, respectively. The powders were studied by electron microscopy, X-ray diffraction and Raman spectroscopy. The copper sulfide main phase is hexagonal 2H-CuS, whereas hexagonal 2H-MoS2 and rhombohedral 3R-MoS2 are characteristic for molybdenum disulfide. The lattice parameters of copper and molybdenum sulfides were calculated. The average particle size of copper sulfide and molybdenum disulfide powders was about 50 nm and 80 nm, respectively.

Nickel-Containing Systems in Reaction of Partial Oxidation of Hydrocarbons

2015 ◽  
Vol 670 ◽  
pp. 33-38 ◽  
Author(s):  
Sergey Galanov ◽  
Olga I. Sidorova ◽  
Vera A. Batyreva
Keyword(s):  
High Temperature ◽  
Average Particle Size ◽  
Reaction Medium ◽  
Oxide Phase ◽  
Average Particle ◽  
Catalytic Layer ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Catalytically Active ◽  
Catalyst Systems

Nickel dispersion, which provides total catalytically active metal surface, is significant for partial catalytic oxidation of natural gas to obtain high purpose products yield and productivity in syngas. The interaction of reaction medium under high reaction temperatures during 20-25 hours promotes the increase of total square of active Ni component for block catalysts obtained with self-propagating high-temperature synthesis, which allows achieving productivity in syngas 7.1·103cm3(syngas)/cm3(catalyst)·hour. It is observed that for catalyst systems obtained with precipitation, chemical composition of oxide phase influences the particles size of metal nickel. For granular catalysts obtained through precipitation after 25-hour exploitation, average particle size (according to CSR) metal nickel is 3-4.5 times smaller than Ni in catalysts obtained with self-propagating high-temperature synthesis. This allows achieving productivity in syngas 8.1·103cm3/сm3·hour, when there is average temperature decrease over the catalytic layer by ~100°С in comparison with blocks acquired through self-propagating high-temperature synthesis.

scholarly journals Self-Propagating High-Temperature Synthesis of Silicon Carbide and Silicon Nitride Nanopowders Composition using Sodium Azide and Halides

2013 ◽  
Vol 16 (1) ◽  
pp. 41 ◽  
Author(s):  
Yu.V. Titova ◽  
A.P. Amosov ◽  
G.V. Bichurov ◽  
D.A. Maidan
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Silicon Nitride ◽  
Combustion Synthesis ◽  
Sodium Azide ◽  
Average Particle Size ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Working Volume

<p>Regularities of self-propagating high-temperature synthesis (SHS) or combustion synthesis (CS) by using “silicon – sodium azide – ammonium hexafluorosilicate – carbon – aluminum” powder mixture in the nitrogen atmosphere were investigated. The thermodynamic analysis of the combustion synthesis was performed. Experimental investigation of the combustion process: the measurement of linear rates of the combustion front propagation and the maximum combustion temperatures was conducted in a laboratory reactor with working volume 4.5 liters. The influence of the components ratio in the initial mixture on the combustion temperature, combustion rate and composition of reaction product was studied. The phase composition of the product synthesized was determined with an X-ray  diffractometer. It was disclosed that the SHS product consists of the composition (mixture) of silicon carbide nanopowder with silicon nitride whiskers and a final halide. Investigation of surface topography and morphology of the product particles was carried out with a scanning electron microscope. Optimal mixture for the synthesis of nanoscale composition based on silicon carbide was determined: “14Si+6NaN<sub>3</sub>+(NH<sub>4</sub>)<sub>2</sub>SiF<sub>6</sub>+15C+Al”. In this case, the SHS product consists of four phases: silicon carbide (β-SiC) – 48.57 wt.%, α-silicon nitride (<em>α</em>-Si<sub>3</sub>N<sub>4</sub>) – 27.04 wt.%, β-silicon nitride (β-Si<sub>3</sub>N<sub>4</sub>) – 5.83 wt.%, and sodium hexafluoroaluminate (Na<sub>3</sub>AlF<sub>6</sub>) – 18.56 wt.%. The average particle size of the composition was in the range of 70–130 nm. It was shown that the composition of the silicon carbide with silicon nitride and the final halide Na<sub>3</sub>AlF<sub>6</sub> playing a role a flux can be used as a modifier of castable aluminum alloys and as a reinforcing phase of aluminomatrix composites.</p>

Production of Al2O3/SiC Nanoparticles from Rice Husk Ash by Self-Propagating High-Temperature Synthesis Process and Ball Milling

2017 ◽  
Vol 904 ◽  
pp. 93-97 ◽  
Author(s):  
Morteza Hoseini ◽  
Ghasem Dini ◽  
Azam Fatemi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Ball Milling ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
Sic Nanoparticles ◽  
High Temperature Synthesis

In this study, silica obtained from the rice husk was used to synthesis of Al2O3/SiC nanoparticles. For this reason, the ash obtained from the burning of the rice husk which contains more than 93 wt. % silica, aluminum and carbon powders with the molar ratios of 3:4:6 were mixed and then compacted into pellets by using a cylindrical die under a pressure 50MPa. In order to conduct the self-propagating high-temperature synthesis (SHS), the produced pellets were placed in an electrical furnace at 850°C under the argon gas atmosphere. Then, a planetary ball milling for 4 to 24h was used to decrease the particle size of the synthesized composite. The results of XRF, XRD, SEM and DLS investigations shown that the rice husk ash can be used to fabricate Al2O3/SiC nanoparticles with an average particle size of about 80 to 65nm via SHS process and ball-milling for 12 to 24h.

Synthesis and Characterization of ZrB2-ZrC Composite Powders from Zircon Sand by Self-Propagating High-Temperature Synthesis Method

2018 ◽  
Vol 934 ◽  
pp. 66-70
Author(s):  
Singsarothai Saowanee ◽  
Niyomwas Sutham ◽  
Tawat Chanadee
Keyword(s):  
High Temperature ◽  
Synthesis Method ◽  
Equilibrium Composition ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Zircon Sand

ZrB2-ZrC composite powders were synthesized from zircon sand by self-propagating high-temperature synthesis (SHS). The reactions were verified and the feasibility of obtaining the predicted products was calculated from the adiabatic temperature (Tad) and the equilibrium composition using the HSC®chemistry program. The results show that the SHS products consisted of ZrB2, ZrC, ZrO2, ZrSiO4, MgO, and Mg2SiO4. Leaching the products with 0.5 M of HCl solution eliminated the by-product of MgO and the intermediate Mg2SiO4phases. The phase composition of the products was characterized by X-ray diffraction (XRD) and the morphologies were characterized by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX).

Correlation of reactant particle size on residual stresses of nanostructured NiAl generated by self-propagating high-temperature synthesis

2009 ◽  
Vol 24 (6) ◽  
pp. 2079-2088
Author(s):  
Iris V. Rivero ◽  
Michelle L. Pantoya ◽  
Karthik Rajamani ◽  
Simon M. Hsiang
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Residual Stresses ◽  
X Ray Diffraction ◽  
Initial Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Composite Production ◽  
Compressive Residual Stresses

This investigation analyzed the effect of reactant particle size on the stress development characteristics of NiAl synthesized through self-propagating high temperature synthesis. Four sample combinations of NiAl were synthesized based on initial particle diameters of the reactants: (i) 10 μm Al and 10 μm Ni (S1), (ii) 10 μm Al and 100 nm Ni (S2), (iii) 50 nm Al and 10 μm Ni (S3), and (iv) 50 nm Al and 100 nm Ni (S4). Characterization of NiAl was performed by parallel comparison of the distribution of residual stresses of the samples prior to and after the reaction. Residual stresses were quantified using x-ray diffraction. Upon characterization it was found that combinations S1, S2, and S3 exhibited tensile residual stresses, while combination S4 exhibited compressive residual stresses. Statistical analysis confirmed that self-propagating high temperature synthesis products derived from nanoparticle reactant sizes exhibited compressive residual stresses offering improved fatigue resistance in composite production.

Synthesis and Characterization of Monodisperse Nanocrystalline HZSM-5 Zeolite

2013 ◽  
Vol 423-426 ◽  
pp. 135-138
Author(s):  
Jun Fang Wei ◽  
Fang Zhu ◽  
Xiao Yan Zhang
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Ammonium Hydroxide ◽  
Crystallization Time ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Influence Of Crystallization

A monodisperse nanocrystalline HZSM-5 zeolite was prepared by varying-temperature synthesis method with aluminum nitrate (Al (NO3)3), tetraethyl orthosilicate (TEOS), and tetrapropyl ammonium hydroxide (TPAOH) as raw materials. X-ray diffraction (XRD) characterization results showed that the crystallinity of HZSM-5 prepared by varying-temperature synthesis method was higher than constant-temperature synthesis . The influence of crystallization temperature and time on morphology and particle size of HZSM-5 is represented by scanning electronic microscopy (SEM) characterization: nanocrystalline HZSM-5 with more regular morphology and smaller particle size can be prepared by varying-temperature synthesis method. The minimum average particle size is 0.3μm. The particle size will grow up to 3.0μm with the crystallization time prolonged.

scholarly journals Thermal, Structural, and Physical Properties of Freeze Dried Tropical Fruit Powder

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Tropical Fruit ◽  
X Ray ◽  
Freeze Dried ◽  
Fruit Powder ◽  
Lcr Meter

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.

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