行进速度对铝合金无针搅拌摩擦改性层性能的影响  

Effect of Traverse Speed on the Properties of Pin-less Friction Stirred Modified Layers of Aluminum Alloys

作　　者：张浩 王优强 段继周 ZHANG Hao;WANG Youqiang;DUAN Jizhou(School of Mechanical and Automotive Engineering,Qingdao University of Technology,Shandong Qingdao 266520,China;Key Laboratory of Marine Environmental Corrosion and Bio-fouling,Institute of Oceanology,Chinese Academy of Sciences,Shandong Qingdao 266071,China;Open Studio for Marine Corrosion and Protection,Qingdao National Laboratory for Marine Science and Technology,Shandong Qingdao 266237,China;Center for Ocean Mega-Science,Chinese Academy of Sciences,Shandong Qingdao 266071,China)

机构地区：[1]青岛理工大学机械与汽车工程学院,山东青岛266520 [2]中国科学院海洋研究所海洋环境腐蚀与生物污损重点实验室,山东青岛266071 [3]青岛海洋科学与技术国家重点实验室海洋腐蚀与防护开放工作室,山东青岛266237 [4]中国科学院海洋大学科学研究中心,山东青岛266071

出　　处：《表面技术》2025年第8期96-106,共11页Surface Technology

基　　金：国家自然科学基金(42076044)。

摘　　要：目的 利用无针搅拌头对2024铝合金表面进行搅拌摩擦加工(FSP)处理,探究行进速度对铝合金改性层性能的影响。方法 采用HT-JC6×8/2搅拌摩擦焊接设备对合金表面进行改性处理。采用电火花线切割在改性层表面截取测试试样(均来自细晶区)。采用5%(体积分数)氟硼酸对改性层试样进行阳极覆膜,以便观察改性层金相组织。通过光学显微镜(OM)、扫描电子显微镜(SEM)、透射电镜(TEM)等,分析了改性层的显微组织、形貌及性能。采用电化学测试,研究不同行进速度下改性层在3.5%(质量分数)Na Cl溶液中的腐蚀行为。结果 改性层晶粒得到显著细化,未发现气孔、裂纹等缺陷。改性层分为细晶区(FG)、变形晶区(TG)和粗晶区(CG)。其中,FG厚度在1 024.3~1 247.3μm。当行进速度为100 mm/min时,改性层的性能最优,其屈服强度(σ_(0.2))、抗拉强度(σ_(b))相比于母材(BM)分别提升了19.2%和24.5%,伸长率(δ)最高可达20.3%;改性层以韧性断裂为主。同时,相较于BM,改性层的耐腐蚀性能最佳,其腐蚀电位(E_(corr))提升至–0.539 V,腐蚀电流密度(J_(corr))降低至2.448×10^(-6) A/cm^(2)。结论 通过对不同行进速度下改性层组织及性能的分析,发现改性层的力学性能和抗腐蚀性能,随着行进速度的增加,均呈现先增强后减弱的趋势。当行进速度达到100 mm/min时,改性层的性能最佳。FSP is a green,environmentally friendly,and efficient surface modification technology.It can reduce the generation of cracks,porosity,and other defects on the alloy surface and improve its surface properties.To increase the depth of the stirring area,traditional FSP generally uses a stirring head with a stirring pin.Nevertheless,inserting the stirring pin into the alloy matrix may destroy the microstructure,which could subsequently lead to a reduction in the overall performance and an accelerated deterioration to the service life of alloy components.To circumvent the issues mentioned,the work aims to utilize a pin-less stirring head to facilitate FSP modification treatment on the surface of the 2024 aluminum alloy(BM).Furthermore,the effect of the traverse speed on the properties of the modified layer of the alloy is investigated.The 2D stirring friction welding equipment model HT-JC6×8/2 was employed to implement a pin-less stirring friction modification treatment on the surface of the aluminum alloy.The process parameters were as follows,including the spindle speed of 1000 r/min,and the traverse speed of 40 mm/min,60 mm/min,80 mm/min,100 mm/min,and 120 mm/min.Tensile and corrosion specimens(from the FG)were extracted from the surface of the modified layer by EDM wire cutting.Anode film of the modified layer specimens was conducted in a 5%HBF4 solution at room temperature to facilitate observation of the metallographic microstructure of the modified layer.The DC voltage was set to 18 V for 150 s.The microstructure,polarized corrosion morphology,tensile fracture morphology,and tensile mechanical properties of the modified layer were analyzed by OM,SEM,TEM,and a YYF/slow strain rate stress corrosion tester.Additionally,a three-electrode system was employed for electrochemical testing of the modified layer to study the corrosion behavior of the modified layer in 3.5%NaCl solution under different traverse speed conditions.An analysis of the tensile and electrochemical corrosion properties of the modified layer spec

关 键 词：无针搅拌摩擦 2024铝合金 表面改性 力学性能 耐腐蚀 行进速度 

分 类 号：TG174[金属学及工艺—金属表面处理]