Effect of drag finish post-processing on surface integrity and wear behavior of Ti-6Al-4V fabricated by laser powder bed fusion additive manufacturing

Abstract

The Additive Manufacturing (AM) process provides opportunities to fabricate products with complex geometries including conformal cooling channels, etc. While having such an advantage, the low surface quality of the products is a disadvantage of laser powder bed fusion (LPBF). Because of that, a post-process is needed to improve the surface quality. Drag Finish (DF) is a surface enhancing operation based on removing small amounts of sawdust from the workpiece that is in contact with abrasive media. This study presents the effect of the drag finish post-processing parameters on wear and surface features of additively manufactured Ti-6Al-4V samples. Processing parameters considered are abrasive media, processing duration, and speed. This study reveals that the surface roughness of as-built specimens can be reduced up to 94% by implementing appropriate process parameters during post-processing operations. Drag finish also results in work hardening on the surface of the specimen and hence increased hardness of the treated surface by 6%. This eventually helps to improve the wear resistance of additively fabricated specimens.