SiC纤维增强高温合金复合材料可行性分析

Feasibility Analysis of SiC Fiber Reinforced Superalloy-based Composite

SiC纤维增强金属基复合材料因耐高温、低密度等特点,在航空航天领域逐渐推广。为进一步提高SiC纤维增强金属基复合材料的使用温度,国内外开始尝试将SiC纤维与高温合金进行复合,以期发挥两者的优点,获得性能更加优良的高温结构材料。但SiC纤维增强高温合金复合材料发展缓慢,诸多尝试均未取得突破性的成功,界面问题是制约该类材料发展的“瓶颈”。虽然在克服界面反应方面也采取了诸多尝试,但该问题并未获得实质性的解决,因此有必要从根源入手对SiC纤维增强高温合金复合材料这一研究方向的可行性进行探讨。本文采用资料研究和实验研究相结合的方式,从SiC纤维增强高温合金复合材料的发展历史、界面反应问题的解决方案、SiC与高温合金界面反应的本质等几个方面逐层展开、一一论述,对SiC纤维增强高温合金复合材料的可行性进行阐述和分析。

SiC fiber reinforced metal-base composite is more and more widely used in aerospace field for its higher temperature capability and lower density.SiC fiber reinforced Ti,Al,Mg based composites have prove to be a great success.But the usage temperature of these composites has been limited by the usage temperature of base metal.In order to further increase the temperature capability of SiC fiber reinforced metal-base composite and obtain high-temperature structural material with better properties,there are some attempts for SiC fiber reinforced superalloy-base composite at home and aboard.However,the development of SiC fiber reinforced superalloy-base composite is in slow development and there has almost no breakthrough success.The bottleneck for the development of SiC fiber reinforced superalloy-base composite is the interface reaction between SiC fiber and superalloy base.Many attempts(such as a variety of interface coatings)have been made to conquer this challenge,while no mature solution has been found.Hence,it is necessary to analyze the feasibility of SiC fiber reinforced superalloy-based composite.In this research,the origin and development of SiC fiber reinforced superalloy-based composites in past decades were narrated.The failure cases and reasons were summarized.Moreover,the attempts of interface coating and disadvantages of this method were analyzed.Experiments and simulations were carried out to investigate the interface reaction between SiC fiber and major superalloy elements.The results show that the reaction between SiC fiber and major superalloy elements is severe and cannot be avoided.Further analysis on the essence of severe reaction between SiC fiber and superalloy was made.The experiment and analysis show that SiC fiber and superalloy are intrinsically incompatible,and the interface reaction trend is severe.Interface coating can hinder the reaction in some extent.But the reaction trend is so severe that any minor failure of coating will result in catastrophic result.The above reasons indicate that it is difficult for SiC fiber reinforced superalloy-base composite to be used commercially in the near future.