硬质相类型对冷喷涂铝基涂层组织与耐磨性的影响  

Effect of Type of the Hard Particle on Microstructure and Wear Performance Properties

作　　者：韩晓辉 刘桥 张繁星 雒晓涛[2] HAN Xiaohui;LIU Qiao;ZHANG Fanxing;LUO Xiaotao(CRRC Qingdao Sifang Rolling Stock Co.,Ltd.,Qingdao 266111,China;State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China;Luoyang Ship Material Research Institute,Luoyang 471023,China)

机构地区：[1]中车青岛四方机车车辆股份有限公司,山东青岛266111 [2]西安交通大学材料科学与工程学院,金属材料强度国家重点实验室,陕西西安710049 [3]洛阳船舶材料研究所,河南洛阳471023

出　　处：《中国材料进展》2024年第2期89-95,123,共8页Materials China

基　　金：国家自然科学基金资助项目(90816024);科技部“973”计划项目(2006CB601206)。

摘　　要：冷喷涂低温固态的材料沉积特性使该方法在热敏感材料高强铝合金的再制造修复方面具有天然优势,然而冷喷涂7系高强铝合金存在结合强度低、硬度和耐磨性能低于同成分基材的难题。对此,主要研究了不同特性硬质颗粒在喷涂粉末中的添加对冷喷涂7050Al合金修复层显微组织、结合强度与摩擦磨损性能的影响规律。以体积分数为30%的脆性Al2O3陶瓷颗粒和韧性的WC-17Co金属陶瓷颗粒为硬质相,在相同参数条件下分别沉积了纯7050Al涂层、7050Al/Al2O3复合涂层与7050Al/WC-17Co复合涂层。采用SEM表征了涂层的横截面组织;依照ASTM C633标准测试了不同硬质相添加对涂层结合强度的影响规律;采用球盘摩擦磨损试验研究了涂层的摩擦磨损行为。结果表明,沉积过程中,脆性的Al2O3颗粒由于不能协调变形,因此与7050Al结合较差且自身会发生碰撞破碎现象;韧性的WC-17Co硬质合金颗粒可以协调变形,因此与7050Al结合较好,且在涂层中含量较Al2O3更高。WC-17Co颗粒在涂层与基材界面处形成的榫卯结构可将7050Al涂层的结合强度由34.5提升到73.2 MPa以上,而Al2O3颗粒的添加对涂层结合强度的影响可以忽略。与7050Al基材相比,WC-17Co硬质合金颗粒的添加可使涂层耐摩擦磨损性能提高8倍以上,而Al2O3颗粒容易剥落的特点使得涂层耐磨性降低50%以上。The low-temperature material deposition characteristic makes cold spray a potential advanced approach to repair and remanufacture high-strength aluminum alloys of high heat susceptibility.However,the cold sprayed 7xxx high-strength Al alloys usually show low bonding strength,lower hardness and wear resistance as compared to the bulk substrate with same composition.In this work,two hard particles were added to the spray powder to study its effects on microstructure,bonding strength,and friction wear performance of the cold-sprayed 7050Al alloy.Brittle Al2O3 and tough WC-17Co metal ceramic particles with a volume fraction of 30%were added into the 7050Al powder under the same parameter conditions to deposit 7050Al/Al2O3 and 7050Al/WC-17Co composite coatings.The cross-sectional microstructure of the coatings was characterized by SEM.The effect of hard particle addi-tions on the bonding strength of the coating was tested ac-cording to ASTM C633 Standard.The friction wear behavior of the coating was studied using ball disc friction-wear tests.The results show that during the deposition,brittle Al2O3 particles could not be deformed,resulting in poor bonding to 7050Al and fracture.However,tough WC-17Co hard al-loy particles can be deformed and result in better bonding to 7050Al.The tenon-mortise structure formed by WC-17Co parti-cles at the coating/substrate interface can significantly increase the bonding strength of the 7050Al coating from 34.5 to a-bove 73.2 MPa,while Al2O3 particles have little effect on the bonding strength.Compared with 7050Al substrate,the addi-tion of WC-17Co ceramic particles can improve the wear resistance by more than 8 times,while brittle Al2O3 particles leads to more than 50%reduction in wear resistance.

关 键 词：冷喷涂 高强铝合金 硬质相类型 显微组织 耐磨性 

分 类 号：TG174[金属学及工艺—金属表面处理]