激光冲击强化镍基单晶高温合金的电化学腐蚀行为  

Electrochemical Corrosion Behavior of Ni-based Single-Crystal Superalloy Treated by Laser Shock Peening

作　　者：耿永祥 郑海忠 李贵发[1,2] 肖怡新 Geng Yongxiang;Zheng Haizhong;Li Guifa;Xiao Yixin(National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China;School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室,江西南昌330063 [2]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《稀有金属材料与工程》2023年第8期2721-2731,共11页Rare Metal Materials and Engineering

基　　金：Youth Science Fund Project of Jiangxi Province(20212BAB214037);National Natural Science Foundation of China(52271057,52071172,51361026);Open Foundation of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology(EG202101419);PhD Research Startup Foundation of Nanchang Hangkong University(EA202001199)。

摘　　要：采用激光冲击强化技术处理了镍基单晶高温合金,随后分别热暴露于750和850℃下2 h,研究了其在3.5%NaCl溶液中的电化学腐蚀行为。结果表明,激光冲击强化处理增加了镍基单晶合金的耐蚀性,这与其诱导的残余压应力和γ/γ′两相中的位错结构有关。γ/γ′两相中非均匀分布的位错增加了两相错配度。热暴露后激光冲击强化试样电化学腐蚀试验表明,残余压应力和两相错配度是影响单晶合金耐蚀性的2个主要因素。残余压应力可以提高单晶合金的耐蚀性,而两相错配度则降低了单晶合金的耐蚀性。此外,单晶合金耐蚀性的提高也与Ta_(2)O_(5)和WO_(3)氧化物的形成有关。Ni-based single-crystal(SC)superalloys were treated by laser shock peening(LSP)and then exposed at 750 and 850°C for 2 h.The electrochemical corrosion behavior of the as-obtained specimens was investigated in 3.5wt%NaCl solution.The results show an increase in the corrosion resistance of SC alloy treated by LSP;it is related to the compressive residual stresses(CRS)and significantly different dislocation structures inγ/γ′phases.The non-uniformly distributed dislocations inγ/γ′phases raise the twophase misfit.The electrochemical corrosion tests of LSP-treated specimens after heat exposure indicate that CRS and two-phase misfit are the two major factors influencing the corrosion resistance of SC alloys.CRS can enhance the corrosion resistance while the twophase misfit deteriorates the corrosion resistance of SC alloys.In addition,the improved corrosion resistance of SC superalloys is linked to the formation of Ta_(2)O_(5)and WO_(3)oxides.

关 键 词：镍基单晶高温合金 激光冲击强化 电化学腐蚀 错配度 残余压应力 

分 类 号：TG132.3[一般工业技术—材料科学与工程] TG665[金属学及工艺—合金] TG172[金属学及工艺—金属学]