In this work the fracture toughness of copper-composite materials was studied. The volume fraction of copper was between 69 and 76 %. The study was carried out with two types of composites. The first type were composites containing spherical copper particles. The second type were composites with copper particles, which were rolled before they were pressed to a bulk material. The analysis of fracture toughness shows, that the composites with spherical particles have a mean fracture toughness of 1.69 MPam 1/2 . The composites with higher aspect ratios of particles have a fracture toughness of 2.66 MPam 1/2 . It corresponds to an increasing of approximatively 55 % for the toughness referred to composites with spherical particles.
