带涂层的TiAlNb合金高温氧化行为  

Oxidation Behaviors of TiAlNb with Coatings at 800℃ and 900℃ Respectively

作　　者：熊玉明[1] 朱圣龙[1] 王福会[1] 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护国家重点实验室,辽宁沈阳110016

出　　处：《稀有金属材料与工程》2006年第2期213-216,共4页Rare Metal Materials and Engineering

基　　金：国家杰出青年基金(59625103);国家高技术研究发展规划;中科院"纳米材料的化学稳定性"重大创新项目资助

摘　　要：研究了带NiCrAlY,TiAlCr及搪瓷涂层的TiAlNb合金分别在800℃和900℃时的氧化行为。结果表明,3种涂层均能在一定程度上对基体合金提供防护,但氧化后,涂层和合金间出现了不同程度的反应和互扩散。氧化时,NiCrAlY涂层发生内氧化,且在NiCrAlY/TiAlNb界面互扩散严重,而界面的某些区域形成的保护性Al2O3虽能有效阻碍氧的内扩散,但也导致涂层从基体表面剥落;TiAlCr涂层表面形成连续Al2O3能对基体提供很好的防护,但涂层/合金界面出现的Nb和Cr的互扩散带可能会影响涂层寿命及基体合金的力学性能。在与TiAl合金接触时,搪瓷变得不稳定,氧化过程中,涂层与合金界面形成一定厚度的反应层,致使涂层与合金间结合力下降。In this present, the oxidation behaviors of TiAlNb intermetallics with and without sputtering NiCrAlY and TiAlCr coatings and enamel coating at 800℃ and 900℃ respectively were studied. The results indicate that TiAlNb bare alloy has the ability to resist oxidation at 800℃ and 900℃ by forming the adhesive layered oxide scale of Nb-doped TiO2 and Al2O3, And the three coatings could protect TiAlNb intermetallics from oxidation at the two temperatures. However, heavy interdiffusion occurr at the interfaces of coatings/TiAlNb after oxidation. A continuous protective Al2O3 scale formed at part of interface of NiCrAlY/TiAlNb to hinder the interdiffusion and the inward-diffusion of oxygen. A protective Al2O3 scale could form on TiAlCr coating during oxidation at elevate temperature. However, the interdiffusion of Nb and Cr at the interface might be detrimental to the long-term oxidation resistance and mechanical performance of the substrate. Enamel coating could provide protection to TiAlNb alloy due to its good thermal chemistry stability and matched thermal expansion coefficient with the substrate. But reaction layer occurred at the interface of enamel/TiAlNb would weaken the adhesive ability of coatings to the substrate.

关 键 词：TiAlNb合金 高温氧化行为 抗高温氧化涂层 

分 类 号：TG172.9[金属学及工艺—金属表面处理]