MECHANICAL ALLOYING AND FRACTURE FEATURES F NON-EQUILIBRIUM Cu-Co ALLOYS
The paper studies the structural, phase and fractographic features of mechanically synthesized non-equilibrium Cu-Co alloys characterized by limited solubility. The components are taken in three different proportions. Mechanical alloying was carried out by high-pressure torsion related to severe plastic deformation methods. As a result of mechanical alloying, the investigated system of components initially insoluble below 800 °C, according to the equilibrium phase diagram, undergoes structural and phase changes consisting in the formation of non-equilibrium solid solutions. With an increase in the proportion of cobalt in the original mixture, the proportion of this element in the solid solution increases after mechanical alloying. This, in turn, affects the appearance of the fracture surface; namely, it changes from brittle-ductile fracture first to brittle fracture and then to mixed one, corresponding to an earlier stage of deformation-induced mechanical alloying.