A Review on Surface Roughness of Metals Parts Fabricated by Selective Laser Melting

Selective laser melting (SLM) is a new additive manufacturing (AM) technology, which has the advantage of high efficiency, high precision, near-net forming, and can be used to fabricate high performance components with complex geometries. All of these characters make SLM a wide array of application in aerospace and biomedical fields. However, the surface quality of parts manufactured via SLM still cannot meet the needs of industrial applications. The optimization of process parameters and different post-treatment processes are the main ways to control the surface quality of SLM-fabricated parts. For the post-treatment process of SLM-manufactured parts, it mainly includes conventional machining, surface blasting, laser polishing, chemical polishing, electrolytic polishing, ultrasonic surface modification, etc. Especially for those parts with specific applications, higher requirements are placed on the surface wear resistance, notch sensitivity, and fluid friction resistance. Therefore, it is necessary to select an appropriate post-treatment process based on the characteristics of the SLM-fabricated parts. Based on the principle of the SLM technology, this paper summarizes the main factors affecting the surface roughness and the main post-treatment processes to improve the surface quality of the SLM-manufactured parts. Finally, the challenges and future development trends of controlling the surface roughness of SLM-manufactured metal parts are prospected and assessed. © 2021, Materials Review Magazine. All right reserved.