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

• Published in: International journal of fatigue Vol. 175; p. 107775
• Main Authors: Karimialavijeh, H., Ghasri-Khouzani, M., Das, A., Pröebstle, M., Martin, É.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2023
• Subjects: Aluminum alloy; Contour scanning; Fatigue life; Laser powder bed fusion; Surface roughness; Laser powder bed fusion; Fatigue life; Surface roughness; Contour scanning; Aluminum alloy
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2023.107775

[Display omitted] •Effect of contour scanning on surface finish and fatigue life of A20X is studied.•Surface roughness of as-printed A20X is mainly controlled by contour scan speed.•Improving average surface roughness by 48% extends the fatigue life by 200%.•Subsurface defects form by a combination of contour scan speed and offset distance.•Surface valleys and surface-connected voids are responsible for failure initiation. 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.