Zheng Yang, Pan Xiaomeng, Ma Yinglei, Liu Shuming, Zang Libin, Chen Yong
School of Mechanical Engineering, Hebei University of Technology, Tianjin 300130, China.
Patent Examination Cooperation (Tianjin) Center of the Patent Office, CNIPA, Tianjin 300304, China.
Materials (Basel). 2019 Apr 3;12(7):1115. doi: 10.3390/ma12071115.
Friction stir welding (FSW) with a Zr interlayer was employed to join dissimilar alloys of 6061 Al and AZ31 Mg. The microstructures of Al/Mg and Al/Zr/Mg joints were investigated by optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDS). The results showed that the central part of the Zr interlayer was smashed and intermixed with the base materials in the stir zone, whereas the undamaged part remained stable at the Al/Mg interface. The formation of Al-Mg intermetallic compounds (IMCs) was suppressed by the Zr interlayer due to its synergetic effects of chemical modification and thermal barrier. The electrochemical measurements revealed a differentiated corrosion behavior for each joint, where the corrosion rate of representative regions increased in the order of Al alloy < Mg alloy < heat-affected zone < stir zone. The immersion tests indicated an enhancement in corrosion resistance for the Al/Zr/Mg joint compared with the Al/Mg joint, which is owing to the mitigated galvanic corrosion between the base materials by the Zr interlayer.
采用带有Zr中间层的搅拌摩擦焊（FSW）来连接6061铝合金和AZ31镁合金这两种异种合金。通过光学显微镜（OM）、扫描电子显微镜（SEM）和能量色散X射线光谱仪（EDS）研究了Al/Mg和Al/Zr/Mg接头的微观结构。结果表明，Zr中间层的中心部分在搅拌区被粉碎并与母材混合，而未受损部分在Al/Mg界面处保持稳定。由于Zr中间层的化学改性和热障协同作用，抑制了Al-Mg金属间化合物（IMC）的形成。电化学测量结果显示每个接头都有不同的腐蚀行为，其中代表性区域的腐蚀速率按铝合金<镁合金<热影响区<搅拌区的顺序增加。浸泡试验表明，与Al/Mg接头相比，Al/Zr/Mg接头的耐腐蚀性有所提高，这是由于Zr中间层减轻了母材之间的电偶腐蚀。
