Unveiling surface roughness in Inconel 718 fabricated by LPBF using high-productivity parameters: A dual method exploration

Abstract

Recent advancements in additive manufacturing and its extension to metallic materials have led to the production of highly technological components with complex geometries and mechanical properties comparable to traditional processes. Despite this, the widespread adoption of additive manufacturing remains limited by low productivity. Additionally, optimizing process parameters to enhance productivity while maintaining high surface quality is challenging due to the intricate relationships between process parameters and surface roughness. This study aims to identify the relationship between process parameters and surface roughness using Inconel 718 specimens produced via laser powder bed fusion. Prismatic specimens were printed using seven combinations of process parameters with progressively increasing productivity. Two methods, traditional profilometry and an optical approach, were compared to assess surface quality under varying process conditions. Results show a strong correlation between process productivity and surface roughness, with higher productivity leading to surface roughness increases up to 200 %. The optical method demonstrated superior sensitivity in detecting sharp peaks and valleys, providing higher detail levels than traditional profilometry. Additionally, the optical method was applied to a practical case where traditional techniques fall short, offering crucial insights for advancing LPBF applications in various industrial sectors.