Ag-Y两相合金在高-低氧压下的高温氧化

OXIDATION OF Ag-8Y DUAL-PHASE ALLOY in 10~5 and 10^(-15)Pa OXYGEN at 700℃

研究了含 8mass%Y的Ag -Y合金在 10 5Pa和 10 - 15Pa两个氧压于 70 0℃的氧化 .结果表明 ,在 10 5Pa的氧化很快 ,并遵循近似的抛物线规律 ;10 - 15Pa的氧化则很慢且偏离抛物线规律 .在高氧压仅发生Y的原位内氧化 ,这主要是氧快速向内渗透而没有Y明显地向外扩散所致 ;在低氧压则生成含Ag颗粒的Y2 O3 外氧化层 ,而其Y的内氧化层则远较高氧压者薄 .内氧化Y2 O3 颗粒沿深度而变化 ,近表面处小并呈圆球状 ,随深度增加逐渐变大并拉长 ;在深处呈针状且垂直合金表面 .此外 。

The oxidation of a silver-based alloy Ag-8Y was studied in 10 5 Pa and 10 -15 Pa oxygen at 700℃.The oxidation rate under high P (O 2) is very fast and follows approximately parabolic rate law,however under low P (O 2) is much slower and quite irregular with large deviations from parabolic behavior.Under high P (O 2) the alloy experiences only an internal oxidation of Y without any significant outward Y diffusion,as a result of a fast oxygen penetration.Under low P (O 2)the alloy forms an almost continuous Y 2O 3 layer containing Ag particles,plus an internal oxidation zone of Y much thinner than under high P (O 2).In both cases pure Ag metal appears on the top surface as a continuous layer for high P (O 2) and as separate particles for low P (O 2).The internal Y 2O 3 particles in the matrix change shape with depth,being small and globular close to the alloy surface but larger and acicular,elongated nearly perpendicularly to the alloy surface,at larger depths.