Effects of Laser Polishing on Surface Characteristics and Wettability of Directed Energy-Deposited 316L Stainless Steel

Author(s)

Souza, Adriel Magalhaes ^[1] ; Ferreira, Rodrigo ^[2] ; Barragan, German ^[3] ; Nunez, Johan Grass ^[1] ; Mariani, Fabio Edson ^[1] ; da Silva, Eraldo Jannone ^[1] ; Coelho, Reginaldo Teixeira ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, Sao Carlos, SP - Brazil

^[2] Fed Inst Pernambuco, Dept Control & Ind Proc, Recife, PE - Brazil

^[3] Univ Pontificia Bolivariana, Grp Invest Ingn Aeroespacial, Fac Ingn Aeronaut, Circular 1 70-01, Medellin, Mde - Colombia

• Document type: Journal article
• Source: Journal of Materials Engineering and Performance; v. 30, n. 9, SI, p. 6752-6765, SEP 2021.
• Web of Science Citations: 0

Abstract

Directed energy deposition (DED) is one of the most used additive manufacturing processes for the fabrication of 3D-metal components. However, surface quality is not always within the limits required for most applications. Post-processing operations can overcome such a limitation. Laser polishing (LP) can be performed with the use of a same energy source and same gripping position, thus improving both surface roughness and functional characteristics (e.g., wettability). However, the literature lacks studies on the process parameters and their influence on roughness and wettability characteristics. This article investigates the influence of LP on surface roughness and wettability of AISI 316L SS produced by DED and proposes equations that predict surface roughness and remelted layer thickness (RLT) as a function of laser power (P). The surfaces were characterized by metallographic analysis, microhardness, surface roughness parameters (S-a, S-z, S-ku, and S-sk), and contact angle. The results showed a reduction of up to 86% in S-a, and the S-z/S-a ratio as a P-function was correlated to a surface improvement. S-ku and S-sk help to better characterize the surface, thus affecting its wettability. The RLT displayed a linear and P-dependent behavior. No alteration in the microstructure/microhardness was observed after the LP. (AU)

• FAPESP's process: 19/10758-4 - Study and development of post-processing in metal parts produced by additive manufacturing: application of high speed machining/grinding and magnetic abrasive finishing process
• Grantee: Adriel Magalhães Souza
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/26362-2 - Study of tungsten carbide (WC) coatings produced by DED Direct Energy Deposition in AISI H13 and 4140 steels
• Grantee: Fábio Edson Mariani
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 16/11309-0 - The study, development and application of a hybrid process: Additive Manufacturing (AM) plus High Speed Machining/Grinding (HSM/G)
• Grantee: Reginaldo Teixeira Coelho
• Support Opportunities: Research Projects - Thematic Grants