RT Journal Article T1 Characterisation of 18Ni 300 steel CT specimens in a fatigue test manufactured by selective laser melting at 0°, 45° and 90° A1 Moreno Cerezo, Pablo A1 Sánchez-Cruces, Manuel Alejandro A1 Moore, Steven A1 Wheatley, Greg A1 López-Crespo, Pablo K1 Ciencia de los materiales AB Maraging steel, 18Ni300, is a high-performance material that shows promising potential for various industrial applications. Selective Laser Melting is utilized in the manufacturing of high-value components. Understanding the fatigue mechanisms of this material is imperative, as its fatigue life is influenced by both surface and internal porosity, as well as defects produced when manufacturing the objects due to the patterns used. The main objective is to analyze the characterization of these pores and clarify their relationship with the fatigue properties of the material under study. Compact tension specimens were manufactured by selective laser melting at three angles (0°, 45° and 90°) with respect to the crack growing direction and fatigue tests were performed. A study of the porosity of the sample was conducted, which established a correlation between the printing angle, growing rate (da/dN curves), and the porosity that is categorised through the aspect ratio and the circularity ratio. It is shown that all manufacturing orientations generate similar pore sizes and area, but the 45° orientation induces pore with slightly higher circularity ratio. The results indicate that the faster fatigue crack growth might be linked to the slight increase in pore area and circularity, and this was observed for 45°. PB Elsevier YR 2024 FD 2024 LK https://hdl.handle.net/10630/35001 UL https://hdl.handle.net/10630/35001 LA eng NO Pablo M. Cerezo, Alejandro S. Cruces, Steven Moore, Greg Wheatley, Pablo Lopez-Crespo, Characterisation of 18Ni 300 steel CT specimens in a fatigue test manufactured by selective laser melting at 0°, 45° and 90°, Theoretical and Applied Fracture Mechanics, Volume 134, Part B, 2024, 104730, ISSN 0167-8442, https://doi.org/10.1016/j.tafmec.2024.104730. NO Universidad de Malaga / CBUA.Programa Operativo FEDER from Junta de Andalucia (Spain) through grant reference UMA18-FEDERJA-250. DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 20 ene 2026