摘要
研究了Ｔｉ３ＡＬ，Ｔｉ３Ａｌ－Ｎｂ及ＴｉＡｌ金属间化合物在９００℃及９５０℃空气中当表面有（０．９Ｎａ，０．１Ｋ）２ＳＯ４盐膜存在时的高温热腐蚀行为．结果表明，Ｔｉ３Ａｌ，ＴｉＡｌ金属间化合物在９００、９５０℃遭受严重的热腐蚀．合金表面均没有形成单一的Ａ１２Ｏ３保护层，而是形成外层为富ＴｉＯ２层，内层为ＴｉＯ２、Ａ１２Ｏ３或Ｎｂ２Ｏ５的混合氧化物层，在氧化膜／合金基体界面形成一些硫化物．合金的腐蚀以电化学机制进行．硫化物的形成也促进了电化学反应的阳极过程．向Ｔｉ３Ａｌ中添加Ｎｂ可以显著地改善其热腐蚀性能，这归因于Ｎｂ促进富Ａｌ氧化物内层的形成．ＴｉＡｌ的耐蚀性能优于Ｔｉ３Ａｌ基合金．
Hot corrosion of Ti3Al, Ti3Al-Nb and TiAl intermetallic compounds in the plesence of a (Na,K)2SO4salt film at 900 and 950 ℃ in air was studied.The experimental results indicate that Ti3AI, Ti3Al-Nb and TiAl alloys suffer from severe hot corrosion. A single protective A12O3 barrier layer doest form on the alloy surface.The electrochemical mechanism is responsible for the hot corrosion,and the formation of sulfides at the alloy/scale interface may accelerate the anodic process.The addition of Nb to Ti3Al results in a significant improvement of hot corrosion resistance of the material.The corrosion resistance of TiAl is found to be superior to that of Ti3AI base alloys.
出处
《中国腐蚀与防护学报》
CAS
CSCD
1994年第4期265-270,共6页
Journal of Chinese Society For Corrosion and Protection
基金
国家自然科学基金
"863"高技术联合资助
关键词
金属间化合物
热腐蚀
TIAI
itanium aluminides
Intermetallic compounds
Hot corrosion
