Influ?ancia da Espessura do Filme Polim??rico Intermedi??rio na Resist?ancia Mec?￠nica de Juntas H?-bridas de Alum?-nio 2024-T3 e CF-PPS Produzidas por Uni?￡o Pontual por Fric?§?￡o

摘要

Friction Spot Joining (FSpJ) is an innovative friction-based joining technique for metal-polymer hybrid structures. Friction spot joints of aluminum alloy 2024-T3 and carbon-fiber reinforced poly(phenylene sulfide) composite laminate (CF-PPS) were produced with an additional PPS film interlayer. Two different film thicknesses were investigated in this study: 100 and 500 ?μm. Lap shear testing demonstrated that the joints produced with 100 ?μm film (2093 ?± 180 N) were stronger than the joints with 500 ?μm (708 ?± 69 N). Additionally, the fracture surface analysis revealed a larger bonding area for the joints with 100 ?μm film (53 ?± 2 mm2) as compared to the joints with 500 ?μm film (40 ?± 1 mm2). Considering the low thermal conductivity of PPS, the thinnest film is more likely to soften by the frictional heat during the joining process. Hence, the low viscosity of the molten PPS favors the wettability of the parts’ surface. Microstructural analyses proved that the metallic nub formation and the interdiffusion of PPS chains between film and composite matrix are also favored for thinner film use. Thus, superior adhesion between the partners is achieved. Therefore, it was concluded that the addition of the thinnest film interlayer leads to stronger joints.