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This work presents the effect of burnishing process including burnishing force, burnishing speed and burnishing conditions on surface properties of Inconel 718 alloy fabricated by laser powder based fusion additive manufacturing. As-built, sand blasted and heat-treated specimens are burnished and final surface properties such as surface roughness, surface topography, and microhardness are presented. The performance of the burnished surface is tested through wear test. This study reveals that burnishing process makes substantial contribution to reduce surface roughness of additively manufactured Inconel 718 alloy. Moreover, surface hardness is notably increased resulting from burnishing process and hence wear resistance of this alloy improved. Wear resistance of as-built specimens was increased by 38% through implementing roller burnishing. Wear resistance of heat-treated specimens is increased by 55% through implementing roller burnishing process.

As with all additive manufacturing processes, selecting appropriate process parameters in the laser powder bed fusion (LPBF) process plays an important role in the surface integrity and mechanical behavior of Inconel 718 components. Hatch distance, laser power, laser scanning speed and layer thickness are the main parameters that can be altered in the LPBF process. This study focuses on the role of laser power and scanning speed when hatch distance is larger than laser spot size on product properties. This work reveals that LPBF process parameters significantly impact the fabricated Inconel 718 material properties. However, although the material properties are enhanced by selecting appropriate process parameters, the components need post-processing methods to have the desired properties. Heat treatment was applied as a post-process to obtain parts with the desired material properties. The effect of heat treatment applied to the parts fabricated at various laser power and laser scanning speeds on the parts’ surface integrity, and mechanical performance is comprehensively presented. Determining the details of the interactions of different production parameters with heat treatment is one of the motivations of this study. The presented results establish that heat treatment can change specimens’ microstructural aspects. The results also show a 10% increase in microhardness and a 14% increase in wear performance of specimens, due to the final state of the microstructure after heat treatment.