On the Possibility of Formation and Properties of Copper–Silver Solid Solutions Under Severe Plastic Deformation

Resumo

Mechanical alloying of Cu and Ag powders in concentrations Cu_1–x–Ag_x (х at.% = 0.1, 0.2, …, 0.9) under high-pressure torsion is investigated. The alloys obtained have a structure of nanograined nonequilibrium FCC solid solutions with positive deviation from Vegard’s law. The hardness of the alloys is 4–6 times higher than of the initial components – copper and silver. The energy and power parameters of treatment of the solid solutions and stages of their formation are calculated from the shear stress measured in situ under high pressure. Thermally induced decomposition of the solid solutions begins from aging under normal conditions, is accelerated upon heating, and ends by short-term heating up to 500°C. It is accompanied by simultaneous development of the processes of gathering recrystallization.