This study investigates the fatigue behaviour of additively manufactured 18Ni300 maraging steel. Specifically, the surface and material parameters impacting fatigue performance are analysed through various post-treatment combinations. Vertically built miniaturised test samples produced by laser powder bed fusion are tested in as-built and age-hardening heat-treated conditions. To utilise the potential of using additive manufacturing for complex-shaped parts in which conventional machining tools could have limited access, vibratory finishing and sand blasting are employed. The fatigue results show that in as-built microstructural condition, both the surface treatments significantly enhanced the fatigue performance, with vibratory finishing outperforming sand blasting owing to better surface finish. After heat treatment, sand-blasted samples performed better than vibratory-finished ones because of higher residual stresses. This competing interaction between post-treatments sheds light on identifying the relative influence of various factors. With systematic postfracture and microstructural analyses highlighting the fatigue influencing factors, recommendations are drawn to select post-treatments to achieve the desired fatigue performance.
Post-treatment selection for tailored fatigue performance of 18Ni300 maraging steel manufactured by laser powder bed fusion
Cutolo A.;
2020-01-01
Abstract
This study investigates the fatigue behaviour of additively manufactured 18Ni300 maraging steel. Specifically, the surface and material parameters impacting fatigue performance are analysed through various post-treatment combinations. Vertically built miniaturised test samples produced by laser powder bed fusion are tested in as-built and age-hardening heat-treated conditions. To utilise the potential of using additive manufacturing for complex-shaped parts in which conventional machining tools could have limited access, vibratory finishing and sand blasting are employed. The fatigue results show that in as-built microstructural condition, both the surface treatments significantly enhanced the fatigue performance, with vibratory finishing outperforming sand blasting owing to better surface finish. After heat treatment, sand-blasted samples performed better than vibratory-finished ones because of higher residual stresses. This competing interaction between post-treatments sheds light on identifying the relative influence of various factors. With systematic postfracture and microstructural analyses highlighting the fatigue influencing factors, recommendations are drawn to select post-treatments to achieve the desired fatigue performance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
