| Abstract Scope |
Electric-vehicle motors need joints that are lightweight, highly conductive, and mechanically strong. Conventional block-to-block bonding cannot deliver uniform, defect-free Al–Cu interfaces. Here, <50 µm copper foil is inserted as an interlayer during diffusion bonding of aluminum and copper. Systematic variation of temperature (450–570 °C), time (5–120 min), and pressure (13–26 MPa) shows that sufficient heat and hold time enable thorough atomic diffusion, while moderate pressure and fine surface finish suppress brittle intermetallics and voids. Reducing pressure from 26 MPa to 13 MPa cuts thickness change from 0.130 mm to 0.044 mm, preserving dimensional stability. The scalable process yields strong, electrically optimized joints that mitigate skin-effect losses, supporting lighter, more efficient EV motor designs and advancing sustainable transportation. |