Evaluation of interfacial toughness curve of bimaterial in submicron scale

A novel method combining the experimental data at only two different mixed mode fractures and an empirical interface toughness function has been proposed to establish the interfacial toughness function of a bimaterial in submicron scale. The modified four-point bend specimen was used in experiment to evaluate the first type of mixed mode fracture, while the sandwiched cantilever specimen was employed to get the second one. An empirical interface toughness function reflecting quite accurately the delamination behavior was adopted as a typical one. The obtained results investigated that the proposed method could be used to calibrate not only the interfacial fracture criteria at pure modes but also at any mixed mode fracture of bimaterials in submicron scale.

► Method was proposed to establish the interface toughness curve of Cu/Si in submicronscale.
► Experiment data at only two different mixed mode fractures was used.
► An empirical interface toughness function was adopted.
► Results investigate method could be used to calibrate the interfacial fracture criteria not only at pure modes but also at any mixed mode fracture.