摘要
TiAl-Nb基合金具有优异的综合性能,在先进飞行器及武器等耐高温部件中有巨大的应用潜力,但其高温抗氧化性能无法满足实际使用需求。综述了TiAl-Nb基合金高温抗氧化防护方面的研究进展,包括TiAl-Nb基合金的多元合金化、表面合金化、抗氧化涂层及其抗氧化机理,通过分析不同氧化防护措施的特性,展望了TiAl-Nb基合金高温抗氧化防护的发展趋势。国内外研究结果显示,通过多元合金化方法改善合金组织,并在氧化过程中促进形成保护性Al_2O_3而抑制形成TiO_2,是提高TiAl-Nb基合金高温抗氧化性能的有效手段。利用表面合金化对合金表面的显微组织和成分进行改善,氧化时促进抗氧化性能优良的Al_2O_3或SiO_2保护膜形成,显著提高了TiAl-Nb基合金的抗氧化性能。但高温下合金化层与基体之间的Al、Si、Ti等元素的互扩散会加剧合金化层的退化,进行表面多元合金化,特别是添加微量活性元素,对促进保护性氧化膜的形成及抑制互扩散有良好效果。通过制备表面抗氧化涂层,在氧化时生成保护性氧化膜,阻碍O的内扩散,能够起到良好的高温抗氧化作用,但需要解决涂层/基体合金的结合力较差和反应扩散等问题,制备复合涂层或扩散阻挡层是解决上述问题的有效途径。
TiAl-Nb based alloys have great application potential in high temperature components of advanced aircrafts and weapons due to excellent overall performance. However, high-temperature oxidation resistance of these alloys could not meet requirements of actual service. Research progress on high-temperature antioxidation protection of TiAl-Nb based alloys was reviewed, covering multi-alloying, surface alloying, oxidation resistant coatings and high-temperature antioxidation mechanisms. Meanwhile, characteristics of different oxidation protection measures were analyzed, and development trend of high-temperature antioxidation protection of TiAl-Nb based alloys were prospected. Domestic and foreign studies showed that multi-alloying was an effective way to promote the high-temperature oxidation resistance of TiAl-Nb based alloys by improving microstructures and/or promoting formation of protective Al2O3 scale while suppressing formation of TiO2 during oxidation. Surface alloying could significantly promote oxidation resistance of TiAl-Nb based alloys by improving microstructures and constituents of alloy surface, and promoting formation of Al2O3 or SiO2 protective films during oxidation. However, inter-diffusion of Al, Si and Ti etc. between alloying layer and the substrates would exacerbate degradation of the alloying layer. Surface multi-alloying especially addition of minor reactive elements had good effects on promoting formation of protective oxide films and suppressing inter-diffusion. Preparing oxidation resistant coatings which formed protective oxide film and suppressed internal diffusion of O during oxidation was also an effective way to achieve excellent high-temperature oxidation resistance of the alloys. However, poor bonding strength and reaction-diffusion between the coatings and substrates should be solved carefully, and preparing composite coatings or diffusion impervious layers is proved to be effective in resolving above problems.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2018年第3期224-230,共7页
Surface Technology
基金
陕西省军民融合基金研究项目(16JMR04)
渭南师范学院重点科研项目(17YKF05)~~
关键词
TiAl-Nb基合金
合金化
表面合金化
高温抗氧化涂层
抗氧化机理
TiAl-Nb based alloy
alloying
surface alloying
high-temperature oxidation resistant coatings
antioxidationmechanisms
