在双元氧化剂中二元合金的双重内氧化

DUAL INTERNAL OXIDATION WITHOUT FORMING EXTERNAL SCALES OF BINARY ALLOYS BY TWO OXIDANTS

对双元氧化剂引起二元固溶合金在无外氧化膜条件下 ,发生两氧化剂分立内氧化层的现象作了重新审视 .在摒弃前人某些假设并考虑可能出现的各种氧化膜结构的前提下 ,提出的理论模型可描述同时发生双元氧化与两者各自单独氧化时各氧化膜厚度之间的关系 ,双元氧化两内氧化层厚度比与它们的扩散系数的关系以及最活泼组元在界面富集的程度等 .藉所提理论还讨论了迄今已报道的有关研究结果 .

By removing some approximations used in previous theories, a new theoretical model was developed for treating the simultaneous internal oxidation of binary solid\|solution alloys by two oxidants, which induced formation of subsequent two internal oxidation regions corresponding separately to the two oxidants but without forming external scales of the most\|noble component. The new theory is able to describe the main phenomena related with this kind of internal oxidation such as: the relation between the overall thickness of internal oxidation simultaneously by two oxidants and those produced by the two oxidants singularly; the ratio between the thickness of the two regions depends critically on the ratio between diffusion coefficients of the two oxidants and the enrichment degree of the most reactive component in the internal oxidation by two oxidants etc. Some experimental results reported in the literature so far are also commented in terms of the present theory.