摘要
利用热重分析、扫描电镜及能谱分析等手段研究了合金中弥散分布的Y ,Y2 O3 及离子注入Y+ 对Fe 2 3Cr 5Al合金 110 0℃恒温氧化行为的影响。不含Y的Fe2 3Cr5Al合金氧化膜起皱 ,长时间氧化后冷却过程中膜发生开裂剥落。合金离子注入 1× 10 1 7Y+ /cm2 后氧化膜粘附性得到了改善。合金中加入弥散的Y或Y2 O3 改变了氧化膜形貌 ,膜平坦致密 ,不开裂剥落。不含Y的Fe2 3Cr5Al合金氧化膜皱褶形貌的形成及膜发生剥落的原因与氧化膜生长机制及合金中S的界面偏聚有关 ,Y提高Fe Cr Al合金氧化膜粘附性的原因主要在于Y易与S形成稳定的硫化物 ,从而阻止了S在膜 /合金界面偏聚。Y提高Al2 O3 膜粘附性的原因还在于改变了Al2 O3 膜的生长机制。
The 1100 ℃ isothermal oxidation behavior of Fe 23Cr 5Al alloy modified by yttrium addition was studied by means of thermogravimetric analysis, scanning electron microscopy and energy dispersive X ray analysis. Yttrium was added to this alloy in the form of (1) metallic addition; (2) yttrium oxide; (3) ion implant. Cracking and spalling occurred on the convoluted scale formed on Y free alloy and exposed the substrate. A flat dense scale without spallation is formed on the yttrium alloying addition or yttrium oxide dispersion alloy. The scale adhesion is also improved by 1×10 17 Y +/cm 2 implantation. The results indicate the convoluted morphology of the scale on Fe 23Cr 5Al 0 21Ti alloy is related to the growth mechanism of the alumina scale, and the spallation of the scale is related to sulfur segregation at the scale/alloy interface. The main reason that the adhesion of alumina scale is improved by yttrium addition lies in: Yttrium is liable to form a stable yttrium sulfide with sulfur in the alloy and prevent sulfur interface from segregation. Another reason is that the growth mechanism of alumina scale is changed by yttrium addition.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2000年第4期329-333,共5页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金!重点项目 (5 92 310 10 )
