engleski

Selective oxidation of zirconium in Zr2Cu

The high-temperature oxidation of Zr2Cu in dry oxygen is characterized by selective oxidation of zirconium. The excess of copper is accumulated in the matrix alloy at the alloy-oxide interface forming the Zr8Cu5 phase. The oxide layer consists of monoclinic ZrO2 and a small amount of CuO. Additionally, tetragonal ZrO2 appears up to 873 K at the surface, and Cu2O is formed above 873 K, deeeper in the oxide layer. The reaction kinetics obeys a parabolic rate law. An activation energy of 54.4 kJ/mol has been estimated in the temperature range 773-1123 K. An anomalous decrease of the oxidation rate occurs at 1155-1223 K, after a strong reaction at 1073-1150 K.

corrosion; oxidation; alloys; Zr2Cu; high temperature; selective

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