Formation of intermetallic compounds （IMCs） during friction stir welding （FSW） of alu- minum/magnesium （AI/Mg） alloys easily results in the pin adhesion and then deteriorates joint formation. The severe pin adhe...Formation of intermetallic compounds （IMCs） during friction stir welding （FSW） of alu- minum/magnesium （AI/Mg） alloys easily results in the pin adhesion and then deteriorates joint formation. The severe pin adhesion transformed the tapered-and-screwed pin into a tapered pin at a low welding speed of 30 mm/min. The pin adhesion problem was solved with the help of ultrasonic. The weldability of Al/Mg alloys was significantly improved due to the good material flow induced by mechanical vibration and the fragments of the IMCs on the surface of a rotating pin caused by acoustic streaming, respectively. A sound joint with ultrasonic contained long Al/Mg interface joining length and complex mixture of AI/Mg alloys in the stir zone, thereby achieving perfect metallurgical bonding and mechanical interlocking. The ultrasonic could broaden process window and then improve tensile properties. The tensile strength of the Al/Mg joint with ultrasonic reached 115 MPa.展开更多
基金supported by the National Natural Science Foundation of China(No.51204111)the Program for Liaoning Excellent Talents in University(No.LJQ2015084)+1 种基金the China Postdoctoral Science Foundation(No.2016M590821)Guangdong Provincial Key Laboratory of Advanced Welding Technology for Ships(No.2017B030302010)
文摘Formation of intermetallic compounds （IMCs） during friction stir welding （FSW） of alu- minum/magnesium （AI/Mg） alloys easily results in the pin adhesion and then deteriorates joint formation. The severe pin adhesion transformed the tapered-and-screwed pin into a tapered pin at a low welding speed of 30 mm/min. The pin adhesion problem was solved with the help of ultrasonic. The weldability of Al/Mg alloys was significantly improved due to the good material flow induced by mechanical vibration and the fragments of the IMCs on the surface of a rotating pin caused by acoustic streaming, respectively. A sound joint with ultrasonic contained long Al/Mg interface joining length and complex mixture of AI/Mg alloys in the stir zone, thereby achieving perfect metallurgical bonding and mechanical interlocking. The ultrasonic could broaden process window and then improve tensile properties. The tensile strength of the Al/Mg joint with ultrasonic reached 115 MPa.
