轴肩直径对5083铝合金FSW接头腐蚀行为和力学性能的影响  

Corrosion Behavior and Mechanical Properties of FSW Joint for 5083 Aluminum Alloy with Different Shaft Shoulder Diameters

作　　者：刘旭 贾瑞灵 张慧霞[2] 郭为民[2] 白玉 马文 Liu Xu;Jia Ruiling;Zhang Huixia;Guo Weimin;Bai Yu;Ma Wen(College of Materials science,Inner Mongolia University of Technology,Inner Mongolia Key Laboratory of Film and Coating,Hohot 010051,China;State Key Laboratory for Marine Corrosion and Protection,Luoyang Ship Material Research Institute(LSMRI),Qingdao 266101,China)

机构地区：[1]内蒙古工业大学材料科学与工程学院内蒙古自治区薄膜与涂层重点实验室,内蒙古呼和浩特010051 [2]中国船舶重工集团公司第七二五研究所海洋腐蚀与防护国家级重点实验室,山东青岛266101

出　　处：《稀有金属》2022年第8期1006-1012,共7页Chinese Journal of Rare Metals

基　　金：内蒙古自然科学基金项目(2021LHMS05013)资助。

摘　　要：对厚度为5 mm的5083铝合金板材进行单面对接搅拌摩擦焊接(FSW),研究了不同轴肩直径(12,14和16 mm)对搅拌摩擦焊接头金相组织、耐蚀性能以及力学性能的影响。结果表明:随着轴肩直径的增加,焊核区晶粒尺寸逐渐增大,第二相尺寸也有所增加,且出现了不同程度的聚集,热机影响区晶粒尺寸的均匀性变差。从热影响区到焊缝中心,电极电位逐渐增加,焊核区的表面膜一直处于此消彼长的稳定状态,而热机影响区和热影响区的表面膜以溶解破裂为主。焊接接头的表层硬度曲线呈“W”型分布,硬度最低值出现在前进侧热影响区上。当搅拌头轴肩直径为14 mm时,焊核区晶粒尺寸细小,第二相尺寸均匀,接头表面的钝化区间较宽,腐蚀电流密度最小,表面膜稳定,耐蚀性能最好。对应接头的抗拉强度为288 MPa,断后伸长率为10.6%,焊接接头系数达到89.6%,接头的塑性和强度均达到最大值。5083 aluminum alloy showed excellent properties such as higher corrosion resistance,light weight and so on in a complex service environment.It could be guaranteed that mechanical properties of the joint were close to that of the base metal and the welding defects generated in fusing welding were reduced or eliminated using friction stir welding(FSW).The diameter of the shaft shoulder was an important parameter because it could lead to different heat input of the FSW joint when the size of diameter varied.This paper studied the influence of shaft shoulder diameter on the microstructure and properties of the FSW joints of 5083 aluminum alloy by controlling a single variable.The rotation speed of the tool was 800 r·min-1,the welding speed was 100 mm·min-1,the shoulder diameter was 12,14 and 16 mm,respectively.The change of the shaft shoulder diameter would vary in the heat input and the degree of agitation to the weld nugget zone(WNZ),the thermo-mechanically affected zone(TMAZ)and the heat-affected zone(HAZ)of the FSW joint,which would inevitably affect the grain size and second phase size,eventually resulting in a change in joint properties.The results showed that with the increase of shaft shoulder diameter,the grain size and the second phase size in the WNZ gradually increased,but the second phase showed aggregation.The grain size in the TMAZ was very uneven.The electrode potential gradually increased from the HAZ to the center of the WNZ.Obvious passivation occurred in the FSW joints with different shaft shoulder diameters.The passive film of the WNZ kept a stable state,while the passive film of the TMAZ and the HAZ was dissolved and broken easily.The hardness profiles of the FSW joints with different diameter were all“W”shape,the lowest hardness values appear on the HAZ located the advancing side.When the shaft shoulder diameter was 14 mm,the average hardness of the FSW joint was higher.By comparing and analysis,the shaft shoulder diameter of the tool was 12 mm,the grain size of the WNZ was the smallest,b

关 键 词：5083铝合金 搅拌摩擦焊接(FSW) 轴肩直径 腐蚀行为 力学性能 

分 类 号：TG453.9[金属学及工艺—焊接]