TY - JOUR
T1 - A new approach to correlate the defect population with the fatigue life of selective laser melted Ti-6Al-4V alloy
AU - Hu, Y.N.
AU - Wu, S.C.
AU - Wu, Z.K.
AU - Zhong, X.L.
AU - Ahmed, S.
AU - Karabal, S.
AU - Xiao, X.H.
AU - Zhang, H.O.
AU - Withers, P.J.
PY - 2020
Y1 - 2020
N2 - Microstructural features and defects arising from selective laser melting (SLM) determine the in-service performance of additively manufactured near-net-shape components. Here the grain type, shape, size and distribution were characterized using electron backscattered diffraction (EBSD). High-resolution synchrotron radiation X-ray computed tomography (CT) was used to quantify the population, morphology and dimensions of porosity and lack of fusion defects. For SLM Ti-6Al-4V alloy, the larger-sized defects in comparison with the α grains are more important for crack initiation, typically leading to poor fatigue resistance and a pronounced variation in fatigue life. The fatigue strength was then evaluated in terms of the defect population using a combination of the statistics of extremes and the Murakami model. Finally, an extended Kitagawa-Takahashi fatigue diagram was established within the framework of defect-tolerant design, which includes a classical safe-life region and the defect-determined lifetime in the finite life region
AB - Microstructural features and defects arising from selective laser melting (SLM) determine the in-service performance of additively manufactured near-net-shape components. Here the grain type, shape, size and distribution were characterized using electron backscattered diffraction (EBSD). High-resolution synchrotron radiation X-ray computed tomography (CT) was used to quantify the population, morphology and dimensions of porosity and lack of fusion defects. For SLM Ti-6Al-4V alloy, the larger-sized defects in comparison with the α grains are more important for crack initiation, typically leading to poor fatigue resistance and a pronounced variation in fatigue life. The fatigue strength was then evaluated in terms of the defect population using a combination of the statistics of extremes and the Murakami model. Finally, an extended Kitagawa-Takahashi fatigue diagram was established within the framework of defect-tolerant design, which includes a classical safe-life region and the defect-determined lifetime in the finite life region
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85081620124&partnerID=MN8TOARS
U2 - 10.1016/j.ijfatigue.2020.105584
DO - 10.1016/j.ijfatigue.2020.105584
M3 - Article
SN - 0142-1123
JO - International Journal of Fatigue
JF - International Journal of Fatigue
M1 - 105584
ER -
