Calculation of precipitate dissolution zone kinetics in oxidising binary two-phase alloys

✍ Scribed by P. Carter; B. Gleeson; D.J. Young

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 593 KB
• Volume: 44
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(96)00054-7

✦ Synopsis

Abstract~xidation of a binary alloy at appropriate oxygen potentials leads to the selective oxidation of one component. When that component is concentrated in a dispersed precipitate within a two-phase alloy, dissolution of the precipitate phase will occur when external oxidation takes place. In this paper a diffusional analysis is used to predict the width of the precipitate-dissolution zone (Xd) formed during such an oxidation process. Solutions to the case of both a stationary and a mobile alloy/scale interface are obtained. The predicted values of X~ derived from both the present and previous theoretical treatments are then compared with recently obtained experimental results on the oxidation behaviour of a Ni-Ni~Si alloy. Predicted values of Xd calculated using the present model were in very close agreement with those obtained experimentally. This is in contrast to the values predicted from previously derived models, which significantly underestimated Xd.