Corrosion performance of selective laser-melted equimolar CrCoNi medium-entropy alloy vs its cast counterpart in 3.5 wt% NaCl

The corrosion behaviour of different planes of a selective laser-melted (SLM) equimolar CrCoNi mediumentropy alloy (MEA) was investigated and compared with its counterpart cast alloy in a 3.5 wt% NaCl solution. The microstructures of the SLM products were characterised, and electrochemical corrosion measurements, corrosion surface morphology observations, and X-ray photoelectron spectroscopy analyses were performed. Compared with the cast MEA, the SLM MEA has an inferior corrosion resistance for its more metallurgical defects and smaller grain size. In the SLM MEA samples, The XY-plane of the SLM MEA has a poorer corrosion resistance than the XZ-plane, which is due to more metallurgical defects and lack of fusion pores on the XY-plane and its higher grain boundary density. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The corrosion behavior of the SLM MEA and cast MEA was compared, revealing that the SLM MEA has inferior corrosion resistance due to metallurgical defects and smaller grain size. Specifically, the XY-plane of the SLM MEA showed poorer corrosion resistance than the XZ-plane, attributed to metallurgical defects, lack of fusion pores, and higher grain boundary density.