摘要
涡轮叶片的使用温度升高将严重降低镍基高温合金IN718的力学性能,高温合金表面需要制备抗氧化涂层来抵抗高温氧化和腐蚀的危害。本文系统研究了简单和Si改性铝化物涂层在1000℃下氧化200 h的微观结构演变。由于尖晶石NiCr_(2)O_(4)相和挥发性Cr_(3)O相的形成,IN718高温合金经氧化后发生严重剥落和失效。对于简单铝化物涂层,稳定的α-Al_(2)O_(3)氧化膜显著提高了抗氧化性,在氧化100~200 h时仅增重0.1 mg/cm^(2)。Si改性铝化物涂层由于外部涂层中存在Cr_(9.1)Si_(0.9)相并具有最大晶粒尺寸,表面快速形成了稳定的SiO_(2)氧化膜,产生较好的保护作用,内部形成的Al_(2)O_(3)氧化物与涂层形成钉扎效应,有效地防止氧化膜分层。Ni_(3)Si相的形成和生长产生了微裂纹,导致在氧化100~200 h时其增重率超过简单铝化物涂层,表明有效调节硅含量对于延长涡轮叶片的使用寿命至关重要。
Due to the increased service temperature of turbine blades,the high temperature conditions seriously deteriorate the mechanical properties of nickel-based superalloys,thus it is necessary to prepare the anti-oxidation coating.This research investigated the microstructure evolutions and oxidation behaviors of simple and silicon-modified aluminide coatings at 1000℃for 200 h.After oxidation,serious spalling out and failure appeared due to spinal NiCr_(2)O_(4) and volatile Cr_(3)O phase formation in the IN718 superalloy.For the aluminide coating,the formation of stableα-Al_(2)O_(3)oxide film significantly improved the oxidation resistance,with a mass gain of only 0.1 mg/cm^(2) during the oxidation of100-200 h.The silicon-modified aluminide coating exhibited the lowest mass gain,rapidly formed stable SiO_(2) oxide film due to the existence of the Cr_(9.1)Si_(0.9)phase and maximum grain size in the external coating,and the internal Al_(2)O_(3) oxide together with the coating formed the pinning effect,effectively preventing the delamination of the oxide film.However,the formation and growth of the Ni_(3)Si phase generated microcracks,leading to its rate of mass gain surpassing that of aluminide coating during oxidation of 100-200 h,which illustrates that effectively regulating the Si content is imperative to prolonging the service life of turbine blades.
作者
戴彦璋
邹俭鹏
宁小智
韦鸿铭
詹汶峄
李飞扬
DAI Yan-zhang;ZOU Jian-peng;NING Xiao-zhi;WEI Hong-ming;ZHAN Wen-yi;LI Fei-yang(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Central Iron and Steel Research Institute,Beijing 100081,China)
基金
Project(kq2208270) supported by the Natural Science Foundation of Changsha City,China
Project(kq2208270) supported by the National Key Laboratory of Heavy-duty Fast and High-power Electric Locomotive Open Project Funding,China。
