Effect of age hardening precipitates on the corrosion performance of laser Powder-Directed energy deposited CuNi2SiCr

Abstract

This study explores Laser Powder ? Direct Energy Deposition (LP-DED) processing of CuNi2SiCr and the effect of heat treatment on corrosion behavior. The findings pave the way to increasing the life of the components and the possibility of refabrication upon failure. LP-DED manufactured CuNi2SiCr was subjected to solution treatment followed by age-hardening at 500? for 1,3,5 and 7 h. The microstructure analysis showed the formation of Cr<inf>3</inf>Ni precipitates due to a higher cooling rate in the LP-DED process. Upon aging, Ni<inf>3</inf>Si, Ni<inf>2</inf>Si, and CrSi<inf>2</inf> precipitates evolved. Due to the Orowan phenomenon, microhardness increases with the aging time as the number of precipitates along the grain boundary increases with the aging time. The 5-hour aged sample exhibited the best corrosion resistance due to precipitation coherency in the matrix and the medium-sized precipitates with uniform precipitation-free zones (PFZ) in the grain boundary. © 2024 Elsevier B.V.