Ultrasonic metal welding has been applied for joining aluminum AA5754 sheets to a thermoset matrix composite consisting in a carbon fiber reinforced epoxy resin (CF/epoxy). To overcome the limitations of thermosetting resins, that, unlike thermoplastic polymers, cannot melt due to their chemical structure, a thermoplastic film of Polyamide 6 (PA6) has been used as a surface layer of the CF/epoxy stack before curing. The functional surface created on the thermoset matrix composite enables a fast welding with a metallic sheet. By a proper selection of welding energy and force, an average adhesion strength of 34.8 MPa has been obtained on CF/epoxy-PA6-AA5754 ultrasonically welded joints. The morphological characterization has revealed that the aluminum-composite interface is characterized by carbon fibers in a direct contact or even embedded in aluminum, whose surface presents pores and crevices due to the pronounced plastic deformation of the Al interfacial area
Hybrid ultrasonic spot welding of aluminum to carbon fiber reinforced epoxy composites
LIONETTO, Francesca
;MAFFEZZOLI, Alfonso
2017-01-01
Abstract
Ultrasonic metal welding has been applied for joining aluminum AA5754 sheets to a thermoset matrix composite consisting in a carbon fiber reinforced epoxy resin (CF/epoxy). To overcome the limitations of thermosetting resins, that, unlike thermoplastic polymers, cannot melt due to their chemical structure, a thermoplastic film of Polyamide 6 (PA6) has been used as a surface layer of the CF/epoxy stack before curing. The functional surface created on the thermoset matrix composite enables a fast welding with a metallic sheet. By a proper selection of welding energy and force, an average adhesion strength of 34.8 MPa has been obtained on CF/epoxy-PA6-AA5754 ultrasonically welded joints. The morphological characterization has revealed that the aluminum-composite interface is characterized by carbon fibers in a direct contact or even embedded in aluminum, whose surface presents pores and crevices due to the pronounced plastic deformation of the Al interfacial areaI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
