三元Cu-20Ni-25Co合金在800℃、0·1 MPa纯氧气中氧化行为研究

Studies on Oxidation Behavior of a Two-Phase Cu-20Ni-25Co Alloy at 800℃ in 0.1 MPa Pure O_2

研究了三元Cu-20Ni-25Co合金在800℃、0．1MPa纯氧气中的氧化行为．结果表明：合金由二相组成，合金基体由富Cu贫Co的α相组成，而Co含量较高的β相则以孤立的岛状物形式分散在基体中．与前面研究的3种不同Co含量的双相Cu—Co合金在600～800℃空气中的氧化行为即所有合金均形成由Ca和Co氧化物组成的混合氧化膜不同，目前研究的Cu-20Ni-25Co合金表面形成了连续的Co2O3层．这主要归因于向Cu-Co合金加入了第三组元Ni，降低了合金表面活泼组元形成氧化物所需的临界浓度，促使合金表面由混合氧化物膜向单一活泼组元氧化物膜的转化．

The oxidation behavior of Cu-20Ni-25Co alloy was studied at 800 ℃ in 0.1 MPa pure oxygen. Results show that the alloy is composed of a mixture of two phases, where that with the largest copper and lowest cobalt content forms the matrix, while the other, much richer in cobalt, form a dispersion of isolated particles. The previous studies on the oxidation of three two-phase Cu-Co with different content of cobalt at 600-800℃ showed that all the alloys form complex scales containing complex mixtm＇es of Cu and Co oxides, where Cu concentrates preferentially in the external regions. The present Cu-20Ni-25Co alloy forms a continuous of Co2O3 layers over the surface of alloy because Cu-20Ni-25Co alloy formed by adding Ni to Cu-Co alloy decrease the critical concentration of forming reactive component oxides.