Strengthen of metal-polymer direct molding bonding via three-dimensional porous mechanical interlocking

This paper proposes a direct metal–polymer forming–bonding method using three-dimensional (3D) porous mechanical interlocking to achieve high-strength metal–polymer connections. In this method, porous copper is initially sintered onto copper plates, followed by the infusion of molten polymer into the pores, forming a robust copper–polymer bonded structure. Incorporating microneedle arrays into the copper plates further enhances the bond between the porous copper and the polymer. Characterization of the pore morphology and mechanical properties confirmed the formation of large-area 3D micro-interlocking. Tensile tests on samples with varying porosities showed connection strengths exceeding 30 MPa, with a maximum recorded strength of 37 MPa. Finite element analysis supported the high bonding strength and provided insights into failure mechanisms. This cost-effective technique offers superior copper–polymer bonding strengths, and introduces novel concepts for composite heat exchanger design and manufacturing.