2mm-thick aluminum alloy 2195 with phosphate anodizing pretreated and no pretreatment were joined to 3mm-thick PEEK (Poly ether-ether-ketone) by laser direct joining process

the differences of joint appearance

microstructure of interface and tensile shear force were analyzed under different process parameters. The results show that Al-PEEK dissimilar joint has an arc shaped melted zone in side of PEEK. Compared to Al-PEEK joints without pretreatment

there are dispersed pores with different size in melted zone but no visible gap at interface for anodized AlPEEK dissimilar joints. Anodizing pretreatment could remarkably strengthen Al-PEEK dissimilar joints. The maximum tensile shear force could reached 4479N (PEEK with width of 30mm)

when laser power at 1400W

welding speed at 3mm/s

while failure position is in PEEK with interface not separated. There is a transition layer between Al and PEEK about thickness of 4μm

the same with anodizing film. In this transition layer

it is speculated that chemical bonding of “Al-O-PEEK” may be formed

according to the variation trend of element Al and O concentration

which is the main reason for improving the joints strength.