冷喷涂参数对7050高强铝合金轴箱体修复层组织和性能的影响  

Effect of Cold Spray Parameters on Microstructure and Properties of 7050 High-strength Al Alloy Journal Box Body Coating

作　　者：韩晓辉 姚小春 曹金山 管益辉 张志坚 王雁鑫 雒晓涛[3] HAN Xiaohui;YAO Xiaochun;CAO Jinshan;GUAN Yihui;ZHANG Zhijian;WANG Yanxin;LUO Xiaotao(CRRC Qingdao Sifang Co.,Ltd.,Shandong Qingdao 266111,China;Shaanxi Tianyuan Intelligent Remanufacturing Co.,Ltd.,Xi'an 710049,China;Xi'an Jiaotong University,Xi'an 710049,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]陕西天元智能再制造股份有限公司,西安710049 [3]西安交通大学,西安710049

出　　处：《表面技术》2024年第5期194-204,共11页Surface Technology

摘　　要：目的解决热加工技术修复高强铝合金存在的基材易开裂、沉积层易氧化、强度性能下降等问题,针对高速列车7050铝合金轴箱体修复需求,利用高压冷喷涂技术的低温固态沉积特性完成轴箱体同质修复。方法采用7050铝合金轴箱体样件为基材,在其表面采用高压冷喷涂技术喷涂同质粉末制备出试样,通过SEM、TEM、显微硬度计、球盘摩擦磨损试验机、万能试验机,以及电化学测试等,分别研究喷涂压力、温度对修复层显微组织、硬度、剪切强度、耐蚀耐磨性能的影响规律。结果修复层组织致密,孔隙率小于0.6%,随着喷涂压力、温度的升高,可进一步降低孔隙率;修复层的平均硬度可达133.1HV0.05,低于基体平均硬度(165.6HV0.05);耐磨性与基体相当,磨损机理为塑性犁削;修复层与基体的剪切强度达到96 MPa以上;修复层的腐蚀电位(−0.77 V,vs.SCE)略低于基体(−0.70 V,vs.SCE),修复层与基体无电偶腐蚀倾向。结论通过高压冷喷涂技术制备了组织致密、结合良好、与基体性能相当的修复层,并采用优化的工艺参数完成了损伤轴箱体的再制造修复,经台架试验证明满足服役工况要求。The 7050 high-strength Al alloys are easily to be cracked and the repair layers are easily oxidized and have much lower strength than the substrate materials when they are repaired with the thermal processing additive manufacturing technologies.To solve such problem,the work takes 7050 high-strength Al alloy journal box body used in high-speed train as an example and adopt cold spray,a low temperature solid-state material deposition process,to construct the repair layer.The 7050 aluminum alloy journal box body was used as the test material,with a specification of 100 mm×65 mm×10 mm.Before high-pressure cold spray,the surface of the test material was cleaned with acetone,and then sandblasted with 20 mesh Al2O3.Subsequently,by applying CS1,CS2,CS3 process parameters,the homogeneous powder was sprayed on the surface by high-pressure cold spray technology to prepare the sample.A DWCS-2000 cold spray system(Shaanxi Dewei Automation Equipment Co.,Ltd.,Xi'an,China)was used for coating deposition and it was equipped with a Laval nozzle with throat diameter of 2 mm,outlet diameter of 5 mm,and divergent section length of 180 mm.During the experiment,N2 was used for both the accelerating gas and powder feeding gas.An electric spark cutting machine was used to cut samples with size 20 mm×20 mm×10 mm,15 mm×15 mm×10 mm along the trajectory direction of the repair layer,and the cross section was polished.The surface morphology and cross-sectional microstructure of the repair layer were observed by Olympus DSX500 optical microscope and scanning electron microscope(SEM).A fine analysis of the interface structure was conducted by transmission electron microscopy(TEM).The microhardness of the repair layer and substrate was measured by microhardness tester(HVS-1000).The wear resistance of the repair layer and substrate was tested by ball and disc friction and wear testing machine(UMT-2MT).The corrosion resistance of the repair layer and the substrate was performed by electrochemical workstation(CS150H).The shear strength betwe

关 键 词：冷喷涂 铝合金 显微组织 剪切强度 耐磨性 耐蚀性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]