Surface modification of binder-jet additive manufactured Inconel 625 via electrospark deposition

Advancements in additive manufacturing have facilitated its adoption in the aerospace industry, where a lower production volume for high-valued components is required. However, the poor surface quality of additively manufactured parts is detrimental to component lifespan and requires additional post-processing steps. Here, we address surface roughness and near-surface porosities in binder-jet additively manufactured Inconel 625 parts using an electrospark deposition (ESD) technique. Localized surface melting and material transfer from the ESD electrode results in a near-surface region with increased density (from 62.9% to 99.2%) and increased hardness (from 109 HV to 962 HV). The use of an AA4043 aluminum alloy electrode forms a nickel aluminide intermetallic coating when deposited on Inconel 625, with the potential for use in applications that require resistance to high temperature oxidation.