Utrasonic Joining of Carbon Fiber Reinforced Thermoplastic and Magnesium Alloy

In this study, the influence of metal surface treatment on the bonding strength in direct bonding of carbon fiber reinforced thermoplastic (CFRTP) and flame retardant magnesium alloy AZX612 (Al-6% Zn-1% Ca-2%) was investigated. As surface treatment, plasma electrolytic oxidation treatment was performed on AZX612 in an aqueous solution of sodium phosphate (0.5 mol/L). The applied voltage Va was changed from 80 V to 160 V to form 0.4 μm to 2 μm porous structure on the surface of the magnesium alloy. As a result of ultrasonic bonding, the shear strength reached 5.7 MPa under the condition that fine pores were formed at a high density (Va: 100V), and 240% improvement in strength was achieved compared to the untreated material.