Evolution of the Structure of CuCrHf Bronze under Dynamic Channel-Angular Pressing and Subsequent Annealing

Abstract— The evolution of the structure of chromium–hafnium bronze under high-speed severe plastic deformation by dynamic channel-angular pressing (DCAP) and subsequent annealing has been studied. It is shown that fragmentation of the structure under DCAP occurs predominately through the twinning mechanism, especially upon two passes. In this case, significant strengthening occurs and the microhardness increases to 1750 MPa. When bronze is annealed, additional strengthening occurs due to the precipitation of Cu₅Hf and Cr particles. The structure of bronze after DCAP has high thermal stability, and maximum hardness is achieved after annealing at 400°C. The strengthening and thermal stability of the structure in chromium–hafnium bronze is higher than in hafnium bronze.