| Autor: |
Gorshkov, B. N., Loskutov, V. S., Gavrish, A. A., Shakh, G. E. |
| Zdroj: |
Powder Metallurgy and Metal Ceramics; December 1981, Vol. 20 Issue: 12 p899-902, 4p |
| Abstrakt: |
In the manufacture of a Eu2O3 powder for plasma-spraying, preparatory treatments such as sintering and plasma spheroidization have no effect on the chemical composition of the starting product. Plasma spheroidization of a Eu2O3 powder increases the amount of the high-temperature phase by 20% compared with sintering, but a spheroidized powder is more suitable for plasma-spraying. At specific plasma jet enthalpies in the range from 12 to 20 kW·sec/g no thermal dissociation of europium oxide or reaction between the compound and the plasma jet takes place. Plasma-deposited layers applied at specific enthalpies ranging from 12 to 15.2 kW·sec/g contain only the monoclinic high-temperature phase of europium oxide. Increasing the specific plasma jet enthalpy in deposition to above 15.2 kW·sec/g leads to the appearance of the cubic europium oxide phase in the coating. The grain size of plasma-deposited Eu2O3 coatings decreases with increasing specific enthalpy of the plasma jet. Increasing the specific enthalpy of the plasma jet from 12 to 15.2 kW·sec/g reduces the crystal lattice parameter c of europium oxide, but further increase in specific enthalpy produces no further change in this parameter. With increasing specific enthalpy of the jet, the crystal lattice parametera of Eu2O3 at first, between 12 and 16.2 kW·sec/g, decreases and then, between 16.2 and 20 kW·sec/g, steadily grows. No chemical reaction takes place between a europium oxide coating and a D16 aluminum alloy substrate. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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