Effect of high pressure torsion on microstructure of Cu-Sn alloys with different content of Hume Rothery phase

• Two Cu–Sn alloys with different amount of ε phase were deformed by HPT.
• Strong α-grain refinement and ε phase dissolution took place in one alloy after HPT.
• No grain refinement or phase transitions took place in the second alloy under HPT.

Two copper alloys with 7.8 and 23 at.% tin with different content of ε Hume Rothery phase were subjected to high pressure torsion (HPT) at room temperature. The initial state of both alloys before HPT was quite different. The first alloy contained the Cu matrix (α-phase) with uniformly distributed precipitates of ε-phase, while another consisted of alternating plates of the ε phase and fine-grained (α + ε) mixture. Strong grain refinement of α phase to the nanometer range and partial dissolution of ε phase in Cu-matrix were observed in the Cu–7.8 at.% Sn alloy after HPT. The Cu–23 at.% Sn alloy after HPT revealed neither the grain refinement nor dissolution of phases.