P. Jenczyk; D.M. Jarząbek; G. Jurczak; S. Nosewicz
International Journal of Mechanical Sciences 311 (2026) 111167
Composite materials have emerged as a critical area of research from both fundamental and applied perspectives, with ongoing efforts aimed at improving their mechanical performance. In such systems, the mechanical behaviour of the matrix–reinforcement interface plays a key role in determining overall strength and durability. This study introduces a novel, integrated methodology for quantifying interfacial bonding strength at the microscale, combining focused ion beam (FIB) micromachining, mechanical testing, atomic force microscopy (AFM) measurements, and finite element modelling (FEM). Microscale bi-material beams containing the interface were prepared by FIB and fractured via in-situ micro-bending using a nanoindenter. A central innovation of this work is the high-resolution AFM characterization of the actual fracture surface topography, which captures the three-dimensional morphology of the interface after failure. This experimentally measured geometry was directly incorporated into FEM simulations using cohesive elements to accurately model fracture damage processes. By calibrating the numerical model with experimental force–displacement data, the interfacial strength and fracture energy were quantitatively determined. For Ni–SiC composites, an average fracture energy of 0.014 J/m² was obtained. This method enables direct, geometry-aware assessment of interfacial strength and offers a versatile platform for studying and optimizing interfaces in a broad range of composite systems.