界面互锁复合Zn层对厚板铝/镁FSW界面组织及力学性能的影响  

Effect of Interfacial Interlocking Composite Zn Interlayer on Interfacial Microstructure and Mechanical Properties of Thick Plate Al/Mg FSW Joint

作　　者：孙既峰 柯黎明 徐洋 邢丽 Sun Jifeng;Ke Liming;Xu Yang;Xing Li(National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China;Zhejiang E.O.Paton Welding Technology Research Institute,Hangzhou 311215,China)

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室,江西南昌330063 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072 [3]浙江巴顿焊接技术研究院,浙江杭州311215

出　　处：《稀有金属材料与工程》2023年第11期3900-3908,共9页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51874179)。

摘　　要：对于铝/镁搅拌摩擦焊(FSW)接头,当母材厚度过大时,容易沿界面形成较厚的脆硬金属间化合物(IMCs),导致接头成形极其困难。本研究创新地采用界面互锁复合Zn层,研究了厚板铝/镁FSW接头界面IMCs演变和接头性能变化规律,为后续实现铝/镁FSW接头的高强度连接提供了理论及实践依据。结果表明,斜对接接头镁侧界面上部生成了平均厚度为69.7μm的低熔点共晶层(Mg+Al_(12)Mg_(17)),中部和下部生成了平均厚度为42.7和21.2μm的IMCs,该IMCs层由Al_(12)Mg_(17)和Al_(3)Mg_(2)组成。相比于斜对接接头,当采用界面互锁复合Zn层时,界面局部位置生成了Al-Mg-Zn相(Al_(5)Mg_(11)Zn_(4))和Mg-Zn相(MgZn_(2)、Mg_(2)Zn_(3))替代了原有的Al-Mg IMCs,最小IMCs厚度仅为3.9μm。拉伸结果表明,接头抗拉强度由斜对接接头的2.7 MPa提高至界面互锁复合Zn层接头的32.3 MPa,这与界面互锁效应和IMCs厚度减薄有关。For Al/Mg friction stir welded(FSW)joints,when the thickness of base metal is too large,thicker brittle and hard intermetallic compounds(IMCs)are easily formed along the interface,which makes joint formation extremely difficult.In this research,the interface interlocking composite Zn interlayer was innovatively used to study the evolution of IMCs at the interface of thick plate Al/Mg FSW joint and the change rule of joint performance.The results show that a low melting point eutectic layer(Mg+Al_(12)Mg_(17))with an average thickness of 69.7μm is formed at the upper part of the magnesium side interface of the oblique butt joint,and IMCs with an average thickness of 42.7 and 21.2μm are formed at the middle and lower part.The IMCs layer consists of Al_(12)Mg_(17)and Al_(3)Mg_(2)。Compared with oblique butt joints,when interfacial interlocking compound Zn interlayer is used,Al-Mg-Zn phase(Al_(5)Mg_(11)Zn_(4))and Mg-Zn phase(MgZn_(2),Mg_(2)Zn_(3))are generated locally at the interface,replacing the original Al-Mg IMCs with a minimum IMCs thickness of 3.9μm.The tensile strength of the joint is increased from 2.7 MPa of oblique butt joint to 32.3 MPa of interfacial interlocking composite Zn interlayer joint,which is related to interfacial interlocking effect and thickness reduction of IMCs.

关 键 词：厚板铝/镁接头 搅拌摩擦焊 界面互锁 Zn中间层 力学性能 

分 类 号：TG453.9[金属学及工艺—焊接] TG146.2[一般工业技术—材料科学与工程]