【摘要】 研究了溅射微晶涂层对K38G在800℃和900℃空气中氧化动力学的影响。发现微晶化后K38G的氧化动力学与经典的抛物线规律存在负偏差。分析认为,微晶化后氧化物形核率大大提高,氧化膜中的扩散由晶格扩散变为晶界短路扩散为主,从而改变了氧化膜的生长动力学。根据Wagner高温氧化的基本理论,对微晶合金高温氧化动力学规律进行了探讨,导出微晶K38G合金氧化动力学遵循四次方规律,即x4=kPt。更多还原

【Abstract】 The oxidation kinetics of microcrystalline K38G was compared with that of normal grain K38G at800℃and900℃in air.It was shown that the oxidation rate of microcrys-talline K38G was heavily decreased.The oxidation kinetics of microcrystalline K38G failed to obey the parabolic law.It was suggested that the oxide scale turned into microcrystalline state since the nuclear probability of oxide was extremely increased.The short circuit diffu sion through oxide scale was dominant.An expression,x 4 =k P t,has been derived for the oxidation kinetics of microcrystalline K38G based upon the model of short circuit diffusion.更多还原