TC4在液体推进剂单推-3中电化学腐蚀机理研究  

Electrochemical Corrosion Mechanism of TC4 in Liquid Propellant DT-3

作　　者：唐占梅 郭伟[1] 蒋榕培[1] 方涛[1] TANG Zhan-mei;GUO Wei;JIANG Rong-pei;FANG Tao(Beijing Institute of Aerospace Testing Technology,Beijing 100074,China)

机构地区：[1]北京航天试验技术研究所,北京100074

出　　处：《推进技术》2022年第12期397-404,共8页Journal of Propulsion Technology

摘　　要：为了开发推进剂/金属材料电化学加速试验技术,需要掌握材料的腐蚀特性。本文采用电化学测试方法,结合扫描电镜(SEM)、光电子能谱(XPS)分析手段,研究了钛合金TC4在液体推进剂单推-3中的电化学腐蚀行为与机理。结果表明:TC4在单推-3中的自腐蚀电流密度约为95nA/cm^(2),腐蚀速率约为0.8μm/a,抗均匀腐蚀性能良好,TC4在单推-3中可长期使用;TC4在单推-3中具有两段不同的钝化电位区间,随着极化电位的正移,最终形成外层为TiO_(2)薄膜、中间Al_(2)O_(3)阻挡层、内层为TiO+Ti2O3的三层结构特征的钝化膜,并具有很正的点蚀电位;单推-3中主要组分肼和硝酸肼对TC4钝化膜的破裂溶解过程具有协同作用。In order to develop electrochemistry accelerated testing technology for propellant/metal materials,it is necessary to master the corrosion characteristics of materials in the propellants.The electrochemical corrosion behaviour and mechanism of titanium alloy TC4 in liquid propellant DT-3 were studied by electrochemical test and scanning electron microscopy(SEM)and photoelectron spectroscopy(XPS).The results show that the corrosion current density of TC4 in DT-3 is about 95nA/cm^(2) and the corrosion rate is about 0.8μm/a,which indicates that TC4 has good uniform corrosion resistance and long lifetime in DT-3.It also shows that there are two different potential intervals for passivation of TC4 in DT-3.With the positive shift of potential,a three-layer characteristic passive film is finally formed with TiO_(2) film as the outer layer and Al_(2)O_(3) as the middle barrier layer and TiO+Ti2O3 as the inner layer while it has a very positive pitting potential.Hydrazine and hydrazine nitrate,the main components of DT-3,have a synergistic effect on the rupture and dissolution process of passive film of TC4.

关 键 词：电化学腐蚀 钛合金 液体推进剂 钝化膜 点蚀电位 

分 类 号：V511.3[航空宇航科学与技术—航空宇航推进理论与工程]