Evolution of the Structure of Tin Bronze and Copper after Dynamic Compression by the Kolsky Method Using a Split Hopkinson Pressure Bar

摘要

The effect of high-speed dynamic compression on the structure and mechanical properties of low-alloyed tin bronze in different initial states (coarse-grained, with additional annealing, and cast, obtained by spun casting) and commercially pure copper of the M1 standard is investigated. The results obtained show that the dynamic compression of tin bronze samples in the coarse-grained initial state causes intensive twinning starting from a strain rate of 2.6·103·s-1. At relatively low deformation rates, the dynamic compression of samples in the initial cast state promotes an increase in their strength characteristics, whereas, with a further strain rate increase, the development of relaxation processes is observed. However, additional homogenization annealing decreases the probability of relaxation processes under loading, which results in the highest possible mechanical characteristics. The studies of the M1 commercially pure copper have shown that variations in the deformation rate much less affect the properties than in case of bronze, and their values are lower due to relaxation processes both under loading and after deformation.