No abstract

The evolution of the structure of Cu-1Sn tin bronze under severe plastic deformation by high-pressure torsion has been studied and compared with that of commercially pure copper. It is demonstrated that high-pressure torsion of bronze results in much higher strengthening and structure refinement than that of commercially pure copper, as the presence of the doping element in the former promotes the retardation of dynamic recrystallization and relaxation processes. Besides, contrary to copper, which undergoes not only dynamic, but also post-dynamic recrystallization, all the bronze samples studied are stable after the HPT at room temperature, and they do not suffer any changes after unloading and prolonged ageing.

Evolution of the structure of tin bronze and copper after dynamic compression by the kolsky method using a split hopkinson pressure bar / A. V.

The effect of severe plastic deformation by 1, 3 and 5 revolutions of high pressure torsion (HPT) on the structure and mechanical properties of low-alloyed hafnium bronze Cu–0.78wt%Hf is studied. In the initial annealed state, hafnium is almost completely bonded into intermetallic com-pounds. It has been found that the structure of all the investigated bronze specimens subjected to HPT is stable and that it remains unchanged after unloading and prolonged ageing at room tempera-ture. It is shown that all the specimens develop a dispersed submicrocrystalline structure gradient along the radius of the disk, with an average crystallite size of 200 nm after 1 revolution to 120 nm after 5 revolutions (at mid-radius). The structure is non-uniform even after 5 revolutions, this being confirmed by microhardness measurements. The high-pressure-torsion behavior of hafnium bronze with Hf bonded into precipitates has much in common with the behavior of pure copper. At the same time, in terms of the stability of the obtained structures at room temperature, the behavior of the alloy under study demonstrates much in common with that of low-alloyed tin bronze.

Specific features of grain structure evolution in HPT-nanostructured tin bronze under subsequent heating / A. V. Stolbovsky,