Gas evolution from zirconium carbide, niobium carbide, and tantalum carbide powders

1986 ◽  
Vol 25 (5) ◽  
pp. 363-366
Author(s):  
A. V. Makeev ◽  
V. V. Khromonozhkin ◽  
A. S. Maskaev ◽  
V. G. Vil'chinskii
Keyword(s):  
Niobium Carbide ◽  
Zirconium Carbide ◽  
Tantalum Carbide ◽  
Gas Evolution

Characterization of Metal-Like Carbides-Graphene Composite Prepared by SPS Method

2015 ◽  
Vol 655 ◽  
pp. 87-91 ◽  
Author(s):  
Piotr Wyzga ◽  
Lucyna Jaworska ◽  
Piotr Putyra ◽  
Marcin Podsiadlo ◽  
Jolanta Cyboron
Keyword(s):  
Niobium Carbide ◽  
Zirconium Carbide ◽  
High Hardness ◽  
Carbide Powder ◽  
Self Diffusion ◽  
Graphene Composite ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
20 Nm

High hardness, good thermal and electrical conductivity make carbides technologically important materials. The high melting temperature and low coefficients of self-diffusion make it difficult to obtain full dense material. In this paper the results of Spark Plasma Sintering (SPS) of transition metal carbides: NbC, TaC, TiC, ZrC, VC with the addition of graphene 10-20 nm x 14 microns in an amount of 2.5 mass % are presented. Powders were mixed in isopropyl alcohol in a planetary ball mill for 1h. The sintering processes was carried out at 2200°C at two different times: 5 and 30 min. Microstructure of the samples was analyzed using scanning electron microscopy. The measurements of density, Young's modulus hardness and electrical properties were carried out, also. The best properties were obtained for titanium carbide powder, sintered for 30 min. The most significant density increase of the sintered carbide–graphene composite by about 5.3% (depending on increasing sintering duration) was obtained for niobium carbide, while the smallest densities change for zirconium carbide.

Synthesis of Nanostructured Tungsten Carbide (WC) from Ammonia Paratungstate-APT and its Characterization by XRD and Rietveld Refinement

2017 ◽  
Vol 899 ◽  
pp. 31-35
Author(s):  
Maria Jose S. Lima ◽  
M.V.M. Souto ◽  
A.S. Souza ◽  
M.M. Karimi ◽  
F.E.S. Silva ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tungsten Carbide ◽  
Niobium Carbide ◽  
High Hardness ◽  
Average Crystallite Size ◽  
Synthesis Temperature ◽  
Tantalum Carbide ◽  
X Rays ◽  
Carbon Reduction ◽  
Nanostructured Tungsten Carbide

The carbides of refractory metals like tungsten carbide (WC), tantalum carbide (TaC) and niobium carbide (NbC), has been extensively studied due to their applications in several areas of industry, because of their specific properties; such as high melting point, high hardness, wear resistance, oxidation resistance and good electrical conductivity. The tungsten carbide, particularly, is generally used at hardmetal industries due to its high hardness and wear resistance. New synthesis techniques have been developed to reduce the synthesis temperature of refractory metal carbides using more reactive precursors and gas-solid reactions for carbon reduction. The result is producing pure carbides suitable properties for production of high quality cemented carbides and more selective catalysts. In this work, pure and nanostructured WC was obtained from the ammonium paratungstate hydrate (APT), at low temperature and short reaction time. Hydrogen (H2) and methane (CH4) were used as a reducing gas and carbon source, respectively. The precursor and obtained product were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results obtained by diffraction of X-rays showed that complete reduction and carburization of APT have been took place resulted in pure WC formation. The average crystallite size was in nanometer order reaching values of approximately 20.8 nm and a surface area (BET) of 26.9 m2/g.

Silicidation of Tantalum Carbide and Zirconium Carbide Powders in a Gaseous SiO Environment

2018 ◽  
Vol 54 (8) ◽  
pp. 779-786
Author(s):  
I. M. Belyaev ◽  
P. V. Istomin ◽  
E. I. Istomina
Keyword(s):  
Zirconium Carbide ◽  
Tantalum Carbide
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