摘要
采用磁控溅射和电弧离子镀技术在γ-TiAl合金表面制备NiCrAlY/Al复合涂层,研究了复合涂层对提高γ-TiAl合金抗高温氧化性能的作用机理。经950℃恒温氧化100 h后,涂层表面未发现裂纹和脱落,涂层试样氧化增重值较基体大幅减小。对氧化层进行了SEM、EDS和XRD分析,结果表明无保护涂层的基体γ-TiAl合金表层疏松多孔,无法抵抗高温环境下氧气对基体合金的侵蚀。复合涂层表面的NiCrAlY镀层在氧化过程中形成了Cr2O3,α-Al2O3和β-NiAl相组成的致密防护涂层,阻隔了氧气与基体的接触,中间的Al层为表层持续生成Al2O3提供了Al源。NiCrAlY/Al复合涂层显著提高了基体在950℃下的抗高温氧化性能。
A NiCrAlY/Al duplex coating was prepared by arc ion plating and magnetron sputtering, The effects of the duplex coating on oxidation at elevated temperature were investigated. After exposure in air at 950 ℃ for 100 h, the mass gain of the NiCrAlY/Al coated specimen is much smaller than that of the uncoated substrate, and no peeling is found in the NiCrAlY/Al coating. SEM, EDS and XRD have been used to study the microstructure, elements distribution vs. depth and phase formation of the two oxidized layers. Due to the loose structure, the scale on the bare substrate could not contribute a reliable protection against intrusive oxygen at high temperature. As an oxygen barrier, the NiCrAlY/Al coating is capable of forming a protective scale which is consisted of Cr2O3, α-Al2O3 and β-NiAl. The AI interlayer plays a role of aluminizing resource for the formation of protective A1203 layer. All the results indicate that the oxidation resistance of β-NiAl alloy has been improved effectively by NiCrAlY/Al duplex coating
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2014年第6期1407-1411,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金面上项目(51174119)
江苏省普通高校研究生科研创新计划(CXZZ12-0149)
中央高校基本科研业务费专项资金
航空科学基金(2012ZF52071)
