TY - JOUR
T1 - Beyond the orthogonal
T2 - On the influence of build orientation on fatigue crack growth in SLM Ti-6Al-4V
AU - Rans, Calvin
AU - Michielssen, Jef
AU - Walker, Megan
AU - Wang, Wandong
AU - Hoen-Velterop, Ludmila ’t
PY - 2018/11/1
Y1 - 2018/11/1
N2 - A challenge in developing an in-depth understanding of the crack growth resistance of Additively Manufactured materials is the fact that their mechanical properties have been shown to be both process and part-geometry dependent. Up to now, no studies have investigated the influence of off-axis (beyond the three orthogonal build orientations) orientations on the fatigue crack growth behaviour of selective laser melted Ti-6Al-4V. Furthermore, the widespread use of compact tension specimens for investigating the material behaviour generates data more suitable for plane-strain conditions, rather than the plane-stress state which is more applicable to many lightweight aerospace structures. To address this gap in knowledge, a comprehensive study was carried out to investigate the influence of off-axis build direction in thin SLM Ti-6Al-4V plates, with a focus on the influence of columnar grain orientation on the fatigue crack growth behaviour. It was found that although a macroscopic columnar grain structure is visible on the specimens, it had no discernible influence on the crack growth resistance when the specimen had undergone a stress relieving or HIP heat treatment.
AB - A challenge in developing an in-depth understanding of the crack growth resistance of Additively Manufactured materials is the fact that their mechanical properties have been shown to be both process and part-geometry dependent. Up to now, no studies have investigated the influence of off-axis (beyond the three orthogonal build orientations) orientations on the fatigue crack growth behaviour of selective laser melted Ti-6Al-4V. Furthermore, the widespread use of compact tension specimens for investigating the material behaviour generates data more suitable for plane-strain conditions, rather than the plane-stress state which is more applicable to many lightweight aerospace structures. To address this gap in knowledge, a comprehensive study was carried out to investigate the influence of off-axis build direction in thin SLM Ti-6Al-4V plates, with a focus on the influence of columnar grain orientation on the fatigue crack growth behaviour. It was found that although a macroscopic columnar grain structure is visible on the specimens, it had no discernible influence on the crack growth resistance when the specimen had undergone a stress relieving or HIP heat treatment.
KW - Additive manufacturing
KW - Anisotropy
KW - Fatigue crack growth
KW - Selective laser melting
KW - Titanium
UR - http://www.scopus.com/inward/record.url?scp=85049330522&partnerID=8YFLogxK
U2 - 10.1016/j.ijfatigue.2018.06.038
DO - 10.1016/j.ijfatigue.2018.06.038
M3 - Article
AN - SCOPUS:85049330522
VL - 116
SP - 344
EP - 354
JO - International Journal of Fatigue
JF - International Journal of Fatigue
SN - 0142-1123
ER -