In this paper correlations between the shear strength of the
polymer–metal interface and the topography of the aluminum
substrate are investigated, considering also the influence of the
reinforcement fibers and the main injection molding process
parameters. When overmolding polymer on a metal support, three
different phenomena take place, differently concurring to the final
adhesion behavior: (a) infiltration of the thermoplastic melt into
the micron-size roughness features of the metal substrate, which is
fostered by high metal substrate temperature, (b) polymer
delamination from the metal substrate, due to polymer differential
shrinkage during cooling, whose in-plane component is effectively
contrasted by high percentage of glass fiber reinforcement, and (c)
glass fiber anchorage, which fastens the polymer plate to the
polymer residues interlocked within the metal substrate.