| Autor: |
Bolgar, A. S., Serbova, M. I., Serebryakova, T. I., Isaeva, L. P., Fesenko, V. V. |
| Zdroj: |
Powder Metallurgy and Metal Ceramics; March 1983, Vol. 22 Issue: 3 p207-211, 5p |
| Abstrakt: |
The mixtures method has been employed for measuring for the first time, using a vacuum calorimetric apparatus, the enthalpy of the borides Nb3B2, NbB0.99, and Nb3B4, in the temperature range 1200–2300°K. More accurate values of this characteristic have been obtained for NbB1.96. Calculations have been made of the variation of enthalpy, heat capacity, and Gibbs reduced energy as functions of temperature for the compounds investigated. Variances, confidence limits, and coefficients of correlation have been determined for the parameters of the equations derived. It is shown that the enthalpy of the compounds investigated steadily grows in the range 1200–2300°K. At temperatures above 1500°K the heat capacity of the niobium borides referred to 1 g-atom in a compound decreases with increasing boron concentration in the compound. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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