Effect of laser contour scan parameters on fatigue performance of A20X fabricated by laser powder bed fusion

Abstract

Laser contour scanning was used to improve the surface finish and fatigue properties of A20X components produced by laser powder bed fusion. The effects of four different contour laser scan speeds and three different offset distances were evaluated using mechanical testing and advanced characterization. The maximum profile valley depth (Rv) improves by 50.5 % when laser scan speed decreases from 850 mm/s to 350 mm/s, resulting in fatigue life improvement by 200%. The laser contour parameters affect the type and number of pores created close to the surface of the specimens. However, subsurface pores do not affect fatigue life since a fully surface-driven failure mechanism was observed in this study.