Механические характеристики ВТ1-0 и сплава Zr-1 МАС.% Nb в различных структурных состояниях в режиме гигацикловой усталости

Abstract

In the present study, we performed the microstructural feature and fatigue failure of technically pure titanium VT1-0 and Zr-1 wt.% Nb alloys in different structural states in the gigacycle fatigue regime. Specimens were loaded using a resonance fatigue machine Shimadzu USF-2000 in gigacycle regime. It was shown that the formed ultrafine-grained structure provides high mechanical properties of the alloys and affects the fatigue life. It was found that the formation of the ultra-fine grained structure in VT1-0 and Zr-1 wt. % Nb alloys leads to an increase in the fatigue limit of titanium by 1.3 times and the zirconium alloy by 1.7 times in the gigacyclic region (109 cycles) when compared to the fine-grained and coarse-grained states. Analysis of fracture surface morphology has revealed the fractured structure in coarse-grained and ultrafine-grained VT1-0 and Zr-1 wt.% Nb alloy samples. Fractures in ultrafine-grained VT1-0 and Zr-1 wt. % Nb alloy samples exhibit quasi-brittle pattern.