Microstructure Evolutions and Properties of Al-Cu Alloy Joint in the Pulsed Power Ultrasonic-Assisted GMAW

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2020,（10）
• 页码范围: 1397-1406
• 页数: 10页
• 语种: 英文

摘要

The pulsed power ultrasonic-assisted gas metal arc welding (PU-GMAW) is a new development hybrid welding method.The influences of the pulsed power ultrasonic on the microstructure evolution of the welded joint of Al-Cu alloy were investigated by using scanning electron microscopy,transmission electron microscope and electron back scattering diffraction.The results showed that the efficient heat input in the PU-GMAW was increased by above 100％ compared with the traditional GMAW.The grain and eutectic of the PU-GMAW weld seam were refined compared with that of the GMAW.Cavitation and acoustic streaming induced the dendrite fragmentation (α-Al) and heterogeneous nucleation,which were the main reasons for the grain refinement.The microhardness of the PU-GMAW welded joint was improved compared with that of the GMAW owing to the change of the eutectic and grain.