Cu-15Ni-15Ag合金在600～700℃空气中的氧化

THE AIR OXIDATION OF Cu-15Ni-15Ag ALLOY AT 600～700℃

研究了Cu - 15Ni- 15Ag合金在 6 0 0～ 70 0℃空气中的氧化 .合金由富Ag的α相与Cu -Ni固溶体 β相组成 ;氧化速率基本服从抛物线规律 ,合金的成膜速率与纯Cu氧化近似 .不同温度下合金均形成了最外层为CuO ,内层为Cu2 O ,NiO以及Ag颗粒组成的复杂氧化膜 .在 70 0℃氧化时观察到典型的Ni的内氧化 ,同时 ,由于Ni优先溶解于CuO中影响了CuO -Cu2 O氧压平衡 ,导致形成了CuO位于Cu2

The oxidation of Cu-15Ni-15Ag alloy in air has been studied at 600～700℃.The alloy contains a mixture of a silver-rich phase (α) with a phase mostly composed of a copper-nickel solid solution (β).Thus, the alloy is ternary two-phase systems containing two reactive metals with different affinity for oxygen plus a noble metal.The oxidation rate of the alloy under constant temperature decreases generally with time and is only approximately parabolic, showing some short periods of accelerated oxidation.The scaling rates of the alloy are substantially similar to those for the oxidation of pure copper, in spite of the presence of silver metal and of NiO in the scales.A region of internal oxidation of nickel of the classical type is observed for oxidation at 700℃.A peculiar structure observed at 700℃is the presence of CuO beneath a Cu 2O layer, which is attributed to an effect of the preferential dissolution of nickel in CuO on the oxygen pressure for the Cu 2O-CuO equilibrium.