Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Influence of microstructure on the fatigue properties of Ti-6Al-4V alloy with equiaxed and fully lamellar structures
Submission Author:
Martin Ferreira Fernandes , SP
Co-Authors:
Martin Ferreira Fernandes, Verônica Velloso, Herman J. C. Voorwald
Presenter: Martin Ferreira Fernandes
doi://10.26678/ABCM.COBEM2023.COB2023-1347
Abstract
Titanium alloys are widely applied in the aeronautical and aerospace industry. The selection of the ideal microstructure to optimize the fatigue behavior of Ti-6Al-4V alloy in aeronautic applications is essential to ensure structural integrity. This work aims to investigate the microstructure effect on the fatigue properties of the Ti-6Al-4V alloy with two different conditions: equiaxed and fully lamellar microstructures. Tensile tests were performed to obtain the mechanical properties and define the stress levels of fatigue tests. Axial fatigue tests were carried out with triangular waveforms and a stress ratio of 0.1 at room temperature. Scanning electron microscopy images of the fracture surfaces were obtained to investigate the fracture nucleation sites. The fatigue tests at the maximum stress level of 95% of the yield strength of each condition showed that the course lamellar microstructure had a fatigue life of about only 22.000 cycles compared to 140.000 cycles of the equiaxed microstructure. The large colonies with the same texture of the lamellar microstructure were responsible for preferential sites for fatigue crack nucleation compared to the equiaxed microstructure with lower grain sizes.
Keywords
Fatigue Life, Titanium alloys, Microstructure, Ti-6Al-4V
