The Effect of Chromium and Zirconium Alloying on the Structure and Properties of Submicrocrystalline Copper Alloys Obtained by Dynamic Channel-Angular Pressing

The paper investigates the evolution of the structure and properties of low-alloy dispersion-hardening alloys based on the Cu–Zr, Cu–Cr, and Cu–Cr–Zr systems under high-rate deformation (~105 s–1) by dynamic channel angular pressing (DCAP) and subsequent annealing (aging) at 200–700°C. The effect of alloying with the microadditives Cr (0.09–0.22%) and Zr (0.04–0.20%) in achieving high hardness of copper with a submicrocrystalline structure obtained by DCAP is studied. The effect of DCAP and subsequent aging on the electrical conductivity of alloys is studied. The sequence of decomposition processes of a copper-based α solid solution with the precipitation of nanoscale particles of the second phases and recrystallization is determined. It is shown that the role of zirconium is due to the precipitation of Cu5Zr phase nanoparticles during DCAP and subsequent annealing on dislocations and subboundaries, their fixation, and reduced mobility, as a result, the process of formation of recrystallization centers slows down, which requires rearrangment (restructuring) of the dislocation structure.