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

We report initial results on the synthesis of monolithic aluminum nitride by burning Al–AlN mixtures in high pressure nitrogen. The objective is to synthesize economically large, near-theoretical density AlN parts. In this work, we begin with compacted mixtures of 10 μm Al and 3 μm AlN powder formed into 7.62 cm diameter by 3.81 cm thick disks having densities up to 60% of theoretical. Then, at N2 pressures up to 180 MPa (26 000 psi), we ignite the disk on one face. The fraction of Al converted to AlN, density, and severity of macroscopic cracking vary with N2 pressure and heat transfer from the sample. Presently, products are inhomogeneous, showing regions of relatively high porosity, regions with no porosity but with AlN in a matrix of Al, and regions of nearly theoretical density AlN.

Download Full-text

Properties of Nanocrystalline Titanium Nitride-Based Materials Prepared by High-Pressure Sintering

Functional Gradient Materials and Surface Layers Prepared by Fine Particles Technology ◽

10.1007/978-94-010-0702-3_18 ◽

2001 ◽

pp. 169-176 ◽

Cited By ~ 1

Author(s):

V. S. Urbanovich

Keyword(s):

High Pressure ◽

Titanium Nitride ◽

High Pressure Sintering ◽

Nanocrystalline Titanium

Download Full-text

Simultaneous Synthesis and Consolidation of Nanostructured ZrB2–ZrO2 Composite

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17578 ◽

2020 ◽

Vol 20 (7) ◽

pp. 4349-4352

Author(s):

Seong-Eun Kim ◽

Jin-Kook Yoon ◽

In-Jin Shon

Keyword(s):

Mechanical Properties ◽

Combustion Synthesis ◽

High Frequency ◽

Combined Effects ◽

Induced Current ◽

Mechanical Pressure ◽

Simultaneous Application ◽

Average Grain Size ◽

One Step ◽

Simultaneous Synthesis

A dense nanostructured 2ZrB2–ZrO2 composite was synthesized by the high-frequency inductionheated combustion synthesis (HFIHCS) method within 2 min in one step from mechanically activated powders of 2B2O3 and 3Zr. Simultaneous combustion synthesis and densification were accomplished under the combined effects of the induced current and mechanical pressure. A highly dense 2ZrB2–ZrO2 composite with relative density of up to 95.5% was produced under the simultaneous application of a pressure of 80 MPa and the induced current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.

Download Full-text

Synthesis and sintering of SiC under high pressure and high temperature

Journal of Materials Research ◽

10.1557/jmr.1999.0121 ◽

1999 ◽

Vol 14 (3) ◽

pp. 906-911 ◽

Cited By ~ 17

Author(s):

S. K. Bhaumik ◽

C. Divakar ◽

S. Usha Devi ◽

A. K. Singh

Keyword(s):

Crystal Structure ◽

Particle Size ◽

High Pressure ◽

Silicon Powder ◽

Synthesis Temperature ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Microscopic Studies ◽

Simultaneous Synthesis

Starting from elemental powders, simultaneous synthesis and compaction of SiC were conducted at 3 GPa pressure and temperatures in the range 2100–2900 K. The sintered compacts were characterized by x-ray diffraction, microhardness measurements, and microscopic studies. The efficiency of formation of SiC was dependent on the particle size of the silicon powder, crystallinity of the reactant carbon, molar ratio of silicon and carbon, and synthesis temperature and time. Carbon in excess of the stoichiometric amount was required to obtain compacts free from residual silicon. The SiC samples, with a Si: C molar ratio 1: 1.05, prepared at 2100 K for 300 s had a density and hardness of 3.21 g/cm3 (98.8% of theoretical density) and 22 GPa, respectively. The crystal structure of the SiC depended on the synthesis temperature. Pure β–SiC in the temperature range 2100–2500 K, and a mixture of α– and β–SiC above 2500 K were obtained. The β–SiC was highly crystalline and nearly defect-free.

Download Full-text

Influence of B4C, SiC and Si3N4 Additions on Microstructures and Selected Properties of Titanium Nitride Matrix Materials Obtained by HPHT Method

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.89.109 ◽

2014 ◽

Vol 89 ◽

pp. 109-114

Author(s):

Jolanta Cyboroń ◽

Piotr Klimczyk ◽

Pawel Figiel ◽

Małgorzata Karolus

Keyword(s):

Fracture Toughness ◽

High Pressure ◽

Phase Composition ◽

High Temperature ◽

Titanium Nitride ◽

Young’S Modulus ◽

Young's Modulus ◽

Physical And Mechanical Properties ◽

Ceramic Phase ◽

Ultra High Temperature Ceramics

The paper presents the results of the High Pressure and High Temperature (HP-HT) sintering and investigation of Ultra High Temperature Ceramics (UHTC) composites of titanium nitride matrix. The aim of this studies were to determine the influence of additives on the ceramic phase composition, microstructure and selected properties. Three different kind of mixtures were prepared. 8 to 22 wt% B4C, SiC and Si3N4were added. Composites were sintered under high-pressure high-temperature conditions (HP-HT) using a Bridgman-type apparatus under pressure about 6 GPa. Materials were sintered at the range of 1450 to 1690 ° C, duration of sintering was 60s. The phase composition, microstructure, and the apparent density, Young's modulus, hardness and fracture toughness KIC (HV), using the Vickers indentation method were examined. Sintered titanium nitride with the 22 wt% silicon carbide participation was characterized the best physical and mechanical properties. For this material the relative density is 99%, the Young's modulus 435 GPa, Vickers hardness 18.3 GPa HV1 and fracture toughness 5.5 MPa∙m1/2.

Download Full-text

Supercritical combustion synthesis of titanium nitride

Symposium (International) on Combustion ◽

10.1016/s0082-0784(96)80009-9 ◽

1996 ◽

Vol 26 (2) ◽

pp. 1875-1881 ◽

Cited By ~ 3

Author(s):

K. Brezinsky ◽

J.A. Brehm ◽

C.K. Law ◽

I. Glassman

Keyword(s):

Titanium Nitride ◽

Combustion Synthesis ◽

Supercritical Combustion

Download Full-text

Simultaneous Synthesis and Consolidation of Nanostructured HfB2–SiC Composite

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.19243 ◽

2021 ◽

Vol 21 (7) ◽

pp. 4011-4015

Author(s):

Seong-Eun Kim ◽

Jin-Kook Yoon ◽

In-Jin Shon

Keyword(s):

Fracture Toughness ◽

Relative Density ◽

Combustion Synthesis ◽

Pulsed Current ◽

Mechanical Pressure ◽

Simultaneous Application ◽

One Step ◽

Simultaneous Synthesis ◽

Short Time ◽

Sintering Method

A dense nanostructured 2HfB2-SiC composite was simultaneously synthesized and consolidated by the pulsed current activated sintering method in one step within very short time (two minutes) from mechanically activated 2Hf, B4C and Si powders. Simultaneous combustion synthesis and consolidation were achieved through the combination of the effects of the pulsed current and mechanical pressure. A highly dense 2HfB2–SiC composite with 97.5% relative density was achieved under the simultaneous application of a pressure of 80 MPa and the pulsed current. The fracture toughness of the 2HfB2–SiC composite was higher than that of monolithic HfB2.

Download Full-text