Heats of Formation of Niobium Carbide and Zirconium Carbide from Combustion Calorimetry

1955 ◽  
Vol 77 (24) ◽  
pp. 6512-6513 ◽  
Author(s):  
Alla D. Mah ◽  
B. J. Boyle
Keyword(s):  
Niobium Carbide ◽  
Zirconium Carbide ◽  
Combustion Calorimetry ◽  
Heats Of Formation

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.

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

Slip system determination in cubic carbides by hardness anisotropy

1972 ◽  
Vol 326 (1566) ◽  
pp. 409-420 ◽  
Keyword(s):  
Slip System ◽  
Temperature Regime ◽  
Niobium Carbide ◽  
High Mobility ◽  
Zirconium Carbide ◽  
Metal Carbides ◽  
Temperature Dependent ◽  
Covalent Bonds ◽  
Temperature Regimes ◽  
Dependent Change

Hardness has been examined as a function of indenter orientation on the (001) surfaces of the cubic transition-metal carbides titanium carbide, vanadium carbide, zirconium carbide and niobium carbide. To emphasize the observed anisotropy a Knoop indenter was used. Experiments have been performed in the temperature range —196 to 610 °C. The anisotropy curves obtained at each temperature have been analysed in terms of operative slip systems. Three different temperature regimes for the anisotropy have been identified. These correspond to the {110} <110> slip system for the low-temperature regime, the {111} <110> slip system for the high-temperature regime and a combination of these two systems for the intermediatetemperature regime. To explain this change in slip system it is proposed that an important temperature dependent change in bonding occurs. A qualitative model is suggested for this change in which an increased density of high mobility electrons increasingly screens the directional covalent bonds as the temperature is raised.

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