Strength and bonding mechanisms in vibration‐welded polycarbonate to polyetherimide joints

Under the right conditions, high strengths are shown to be achievable in vibration welded polycarbonate to polyetherimide Joints. While welding of thermoplastic interfaces of the same material can be understood in terms of interchain diffusion at elevated temperatures, this mechanism is severely limited in the case of dissimilar materials. Scanning electron microscopy is used to show that part of the bond strength in such dissimilar materials results from mechanical interlocking of the two polymers, which is caused by viscous mixing. The effects of the weld parameters on the weld morphology are considered in detail.