TC4表面TiN/Ti涂层的热腐蚀行为研究及第一性原理计算  

Hot Corrosion Behavior and Its First Principle Calculation of TiN/Ti Coating on TC4 Substrate

作　　者：孙志平[1] 郭红星 唐昌伟 何光宇[2] 李玉琴[2] 陈永刚[3] SUN Zhiping;GUO Hongxing;TANG Changwei;HE Guangyu;LI Yuqin;CHEN Yonggang(School of Materials Science and Engineering,Chang'an University,Xi'an 710064,China;Science and Technology on Plasma Dynamics Laboratory,Air Force Engineering University,Xi'an 710038,China;Supercomputing Center,Dalian University of Technology,Liaoning Dalian 116024,China)

机构地区：[1]长安大学材料科学与工程学院,西安710064 [2]空军工程大学等离子体动力学重点实验室,西安710038 [3]大连理工大学超级计算中心,辽宁大连116024

出　　处：《表面技术》2024年第10期156-166,共11页Surface Technology

基　　金：陕西省重点研发计划(2023-YBGY-435)。

摘　　要：目的综合评估涂层性能、延长压气机叶片的使用寿命,进行TiN/Ti涂层及冲蚀后TiN/Ti涂层的热腐蚀行为机制研究。方法进行了完整TiN/Ti涂层及冲蚀后TiN/Ti涂层300℃/120h的热腐蚀实验,腐蚀介质为95%(质量分数)Na_(2)SO_(4)+5%(质量分数)NaCl。冲蚀实验采用形状不规则的SiO_(2)颗粒,冲蚀角为45°,冲蚀速度为130 m/s,供砂速率为6.4 g/min。建立了完整TiN涂层、表面具有孔洞的TiN涂层及表面具有Ti液滴的TiN涂层3种第一性原理腐蚀计算模型。结果TiN/Ti涂层热腐蚀后,液滴处发生氧化并且变得疏松;样品切割边缘产生腐蚀锈迹,最终出现鼓包和裂纹;冲蚀后,涂层表面的完整性受到破坏,相较于未冲蚀区域,冲蚀坑周围更容易出现腐蚀。在热腐蚀过程中,SO_(4)^(2-)中的O和完整TiN涂层中的Ti以及液滴中的Ti电子云团接触,存在电荷转移及成键倾向,具体为Ti失电子、O得电子,腐蚀主要发生在SO_(4)^(2-)中的O与Ti之间。结论第一性原理计算结果与热腐蚀的实验结果相一致,第一性原理计算结果可以从微观上反映液滴和孔洞等缺陷对涂层热腐蚀行为的影响,能够为分析涂层的热腐蚀机制提供理论依据。When helicopters take off and land in the desert areas,the compressor blades of titanium alloys are impacted by sand particles.TiN/Ti coating is used for the protection of compressor blades against erosion due to its excellent performance.During service of the aircraft,chloride ions in humid coastal environment,S in the industrial atmosphere and impurities generated from fuel combustion could cause hot corrosion to the compressor blades and affect the comprehensive performance of the compressor.Currently,there are relatively abundant researches on the erosion resistance of TiN/Ti coating,but the research of hot corrosion behavior of TiN/Ti coating is limited.The study on the coupled behavior of hot corrosion and erosion is an important basis for the overall evolution of TiN/Ti coating.In this work,the TiN/Ti coating was prepared on Ti6Al4V(TC4)titanium alloy substrate by Metal Vapor Vacuum Arc(MEVVA)and Filtered Cathodic Vacuum Arc(FCVA)process,and the hot corrosion experiment of intact TiN/Ti coating and eroded TiN/Ti coating were carried out at 300℃/120 h.The corrosion medium was 95%Na_(2)SO_(4)+5%NaCl.The erosion experiment was carried out with irregularly shaped SiO_(2) particles.The erosion angle was 45°,the erosion speed was 130 m/s,and the sand supply rate was 6.4 g/min.The hot corrosive microstructures of the intact TiN/Ti coating and eroded TiN/Ti coating were analyzed by Scanning Electron Microscopy(SEM)and Energy Dispersive Spectroscopy(EDS).After the hot corrosion of TiN/Ti coating,the droplets were oxidized and corroded to be loose,and the morphology of the intact area of the TiN/Ti coating remained almost unchanged.The corrosion rust was produced at the cutting edge of the TiN/Ti coating,and the columnar structure of the TiN/Ti coating of the corrosion rust area was blurred,and granular corrosion products and irregular corrosion pits gradually appeared,eventually leading to bulging and cracking.After erosion,the erosion pits on the surface of the TiN/Ti coating destroyed the integrity of the coat

关 键 词：氮化钛涂层 热腐蚀行为 冲蚀 第一性原理 电荷转移 

分 类 号：TG174.4[金属学及工艺—金属表面处理]