The present work is aimed at exploring the applicability of the theory of critical distances (TCD) to the notch fatigue prognosis of the biomedical titanium Grade 23 (aka Ti-6Al-4V ELI) additively manufactured via selective laser melting (SLM). Particular attention is paid on investigating how the defectiveness influences the material critical length as well as the path followed by the fatigue cracks after nucleation. This latter aspect is of crucial importance, as the notch-crack equivalence postulated by TCD is reasonable only when the position selected for the critical point or the stress-averaging length reflects the actual path of the crack emanating from the notch tip. Specifically, fully-reversed axial fatigue tests are carried out on notched samples. Notches are either directly introduced into the samples via SLM or post-sintering machined via turning. The critical distance lengths are estimated according to critical distance inverse search procedure recently proposed by the authors (Santus et al., Int. J. Fatigue, vol.106 (2018) pp.208-218).
Crack path and notch fatigue strength of Ti-6Al-4V ELI additively manufactured via selective laser melting: Defect sensitivity
C. Santus
2018-01-01
Abstract
The present work is aimed at exploring the applicability of the theory of critical distances (TCD) to the notch fatigue prognosis of the biomedical titanium Grade 23 (aka Ti-6Al-4V ELI) additively manufactured via selective laser melting (SLM). Particular attention is paid on investigating how the defectiveness influences the material critical length as well as the path followed by the fatigue cracks after nucleation. This latter aspect is of crucial importance, as the notch-crack equivalence postulated by TCD is reasonable only when the position selected for the critical point or the stress-averaging length reflects the actual path of the crack emanating from the notch tip. Specifically, fully-reversed axial fatigue tests are carried out on notched samples. Notches are either directly introduced into the samples via SLM or post-sintering machined via turning. The critical distance lengths are estimated according to critical distance inverse search procedure recently proposed by the authors (Santus et al., Int. J. Fatigue, vol.106 (2018) pp.208-218).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
