On the damage mechanisms during compressive dwell-fatigue of β-annealed Ti-6242S alloy

• Published in: International journal of fatigue 2021-05, Vol.146, p.106158, Article 106158
• Main Authors: Rezaei, M., Zarei-Hanzaki, A., Anousheh, A.S., Abedi, H.R., Pahlevani, F., Hossain, R., Sahajwalla, V., Berto, F.
• Format: Article
• Language: English
• Subjects: Annealing; Compressive loading; Constant load; Crack initiation; Crack propagation; Cross slip; Damage; Damage mechanism; Dwell time; Fractography; Grain refinement; Materials fatigue; Metal fatigue; Performance degradation; Shearing; Stacking faults; Stress propagation; Titanium alloys; Titanium base alloys
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2021.106158

[Display omitted] •Unveiling distinction between microstructural response to conventional and dwell fatigue.•Effect of compressive dwell time on microstructure evolution.•Fatigue damage mechanisms at different stress levels and temperatures.•Globularization of alpha and beta phases during dwell fatigue at low temperature.•Formation of alpha nano grains through compressive dwell-fatigue. The present study contends with unveiling the damage mechanisms during compressive dwell-fatigue of β-annealed Ti-6242S alloy. The shearing/displacement of lamellar phases, stacking fault nodes formation, and formation of coarse grains (under the lower stress level) are identified as key factors influencing crack initiation and propagation which mainly contribute in fatigue performance deterioration. Such phenomenal evolutions are interconnected with the microstructure evolution, i.e. globularization and grain refinement of lamellar phases, which can be justified considering the dwell time at maximum applied load by providing a proper condition for (i) activation of multiple slip systems, and (ii) dislocation cross-slip, and substructure development.