Accumulative HPT of Zr-based bulk metallic glasses

•“Accumulative HPT” – to achieve a high strain in hard materials, including BMGs.•Accumulative HPT-effective method of processing for difficult-to-deform materials.•The structure of Zr-BMG during accumulative HPT transforms much more significantly than in the HPT. Studies show that with the HPT of bulk metallic glass, the actual achievable strain is significantly lower than the one predicted by the equation γ=2πnR/h. Such a discrepancy can be explained by the effect of “slippage” during the HPT. The authors proposed a new method − “accumulative HPT” − to achieve a high strain in hard materials, including BMGs. In the accumulative HPT procedure, a sample undergoes several cycles: “HPT n = 1 revolution → cutting a sample into pieces → pressing of stacked parts on the anvils and subsequent HPT n = 1”. At the last stage, the stacked segments are subjected to HPT with many revolutions (n ≥ 3) whereby the sample is consolidated into a monolithic disk. As a result, the material receives a significant total strain by pressing and torsion. The article presents the first results of the “accumulative HPT” processing of a Zr-based BMG and a crystallized Zr-based intermetallic.