摘要
为了提高Ti6Al4V(TC4)钛合金的耐磨性与耐蚀性,采用微弧氧化(MAO)、低温等离子体氮化(PN)和微弧氧化后等离子体氮化(MAO-PN)的工艺分别对TC4钛合金进行表面改性,然后采用扫描电子显微镜、摩擦磨损实验机与电化学工作站研究了基体与3种工艺改性后样品的显微形貌、摩擦与耐蚀性能。结果表明:MAO与MAO-PN样品以金红石型TiO_(2)和锐钛矿型TiO_(2)相为主。PN样品的显微硬度为(602±10) HV_(0.05),MAO-PN样品的显微硬度为(1 232±20) HV_(0.05),显著高于TC4钛合金基体的显微硬度(352±5) HV_(0.05)。在大气环境中,相比TC4钛合金基体,MAO与MAO-PN样品的磨损率由1.48×10^(-3)mm^(3)/(N·m)分别降至5.54×10^(-4)mm^(3)/(N·m)与3.64×10^(-4)mm^(3)/(N·m)。在盐酸溶液的润滑下,相比TC4钛合金基体,MAO与MAO-PN样品的摩擦系数由0.35分别降至0.25与0.18,磨损率由3.62×10^(-4)mm^(3)/(N·m)分别大幅度降至3.50×10^(-6)mm^(3)/(N·m)与1.57×10^(-6)mm^(3)/(N·m),这表明微弧预氧化能够大幅度提高等离子体氮化层的耐磨性。在盐酸溶液中,MAO和MAO-PN样品的磨损机制为磨粒磨损,在大气环境与盐酸溶液润滑条件下,TC4钛合金和PN样品的磨损机制为黏着磨损。MAO-PN复合改性层在盐酸溶液中具有较低的腐蚀电流密度(0.015μA/cm^(2))以及较高的阻抗值(9.90×10^(5)Ω·cm^(2)),说明微弧预氧化工艺能显著提高钛合金等离子体氮化层的耐蚀性。
In order to improve the wear resistance and corrosion resistance of Ti6Al4V(TC4)titanium alloy,surface modification of TC4 titanium alloy was carried out using micro-arc oxidation(MAO),low-temperature plasma nitriding(PN)and plasma nitriding after micro-arc oxidation.Subsequently,the microscopic morphology,friction and corrosion resistance of the substate and the samples modified by three processes were studied by scanning electron microscopy,friction and wear testing machine and electrochemical workstation.Results showed that the micro-arc oxidation layer was mainly composed of rutile TiO_(2) and anatase TiO_(2) phases.The microhardness of the PN sample was(602±10)HVo.o5,and the microhardness of the MAO-PN sample was(1232+20)HV_(0.05),significantly higher than the microhardness of the TC4 titanium alloy substrate(352+5)HV_(0.05).In the atmospheric environment,compared to the TC4 titanium alloy substrate,the wear rates of MAO and MA0-PN samples decreased from 1.48×10^(-3)mm^(3) to 5.54×10^(-4)mm^(3)/(N·m) and 3.64×10^(-4)mm^(3)/(N·m),respectively.Under the lubrication of hydrochloric acid solution,compared with TC4 titanium alloy substrate,the friction coefficient of MAO and MAO-PN samples decreased from 0.35 to 0.25 and 0.18,respectively,and the wear rate decreased significantly from 3.62×10^(-4)mm^(3)/(N·m) to 3.50×10^(-6)mm^(3)/(N·m) and 1.57×10^(-6)mm^(3)/(N·m),respectively.This indicated that micro-arc pre-oxidation could greatly improve the wear resistance of plasma nitride layer.In hydrochloric acid solution,both MAO and MAO-PN samples exhibited abrasive wear mechanisms,while under atmospheric conditions and hydrochloric acid lubrication,TC4 titanium alloy and PN samples demonstrated adhesive wear mechanisms.Furthermore,the MAO-PN composite modified layer exhibited a lower corrosion current density(0.015μA/cm)and higher impedance value(9.90×10^(5)Ω·cm^(2)) in hydrochloric acid solution,indicating that the micro-arc pre-oxidation process significantly enhanced the corrosion resistance of the plasma-nitrided titanium alloy layer.
作者
杨嘉乐
徐立新
李东山
彭振军
张广安
姜长军
YANG Jiale;XU Lixin;LI Dongshan;PENG Zhenjun;ZHANG Guangan;JIANG Changjun(College of Materials Science and Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730030,China;Gansu Oute New Material Technology Co.,Ltd.,Lanzhou 730200,China)
出处
《材料保护》
2025年第6期102-115,共14页
Materials Protection
基金
基础科学研究计划(No.JCKY2023130C005)。
关键词
TC4钛合金
等离子体氮化
微弧预氧化
摩擦磨损
耐蚀性
TC4 titanium alloy
plasma nitriding
micro-arc pre-oxidation
friction and wear
corrosion resistance
