Effect of HPT and accumulative HPT on structure formation and microhardness of the novel Ti18Zr15Nb alloy

[Display omitted] •“Accumulative HPT” – ACCHPT to achieve a high strain in Ti-alloys.•The β-phase is a main in initial Ti18Zr15Nb alloy, after HPT and ACC HPT.•The nanocrystalline structure formed in Ti18Zr15Nb alloy after HPT. Effect of HPT and accumulative HPT on the Ti18Zr15Nb biomedical alloy has been studied. According to the XRD and TEM data, the β-phase is a main phase in the alloy both in the initial state and after processing by HPT and accumulative HPT. The β-phase X-ray line width after HPT processing, and especially after ACC HPT processing has drastically increased as a result of an increase in defect concentration and grain refinement. According to TEM, the grains after HPT processing for n = 10 revolutions are refined in some regions down to 10–30 nm. As a result of HPT processing, the alloy’s microhardness has noticeably increased, which indicates an increase in strength and yield stress together with the preservation of the β-state.