Corrosion Screening of Additively Manufactured Ni-Al Bronze Alloy in a Marine Service Environment

Abstract The rapid prototyping capabilities of additive manufacturing (AM) requires rapid screening protocols for vetting AM performance, especially in realistic service environments. The continually evolving developments in AM processes create a challenge for authorities tasked with qualifying AM components on a timescale comparable to the rate at which a part can be designed, printed, prepped for service, and then reworked between different iterations. A procedure for accelerated corrosion assessment was developed to rapidly screen AM Ni-Al Bronze (NAB) in marine environments. The procedure characterizes AM metals in terms of print quality and corrosion behavior relative to traditionally manufactured, cast components. The primary objective of this work was to assess the success of a rapid screening method in ranking the performance of various lots of AM NAB across different printing technologies and sample preparation. Direct comparative assessments of the effects certain variables have on corrosion behavior will be made, where possible. These samples were tested in the laboratory and exposed at the Navy Research Laboratory (NRL)(1) marine corrosion test site at Key West. Samples were analyzed to determine the extent to which accelerated testing protocols decreased the time needed to differentiate or classify corrosion susceptibility in a faithfully reproducible manner.