Cavitation erosion and corrosion behavior of LPBF and conventionally produced CuZn42 alloy

Abstract Lead-free biphasic brasses are attractive for fluid-handling components due to their environmental and regulatory advantages. However, the absence of lead reduces machinability, prompting the need for alternative strategies to optimize component design and performance. In this context, additive manufacturing offers new opportunities for geometrical customization and material efficiency. The present study evaluates the corrosion and cavitation-erosion performance of CuZn42 (CW510L) produced by laser powder bed fusion (LPBF), in comparison with conventionally extruded material. Microstructural characterization reveals a layered, anisotropic architecture with residual porosity and evidence of Zn depletion relative to the wrought bar, features that concentrate stress and influence the stability and distribution of the α and β phases. Under vibratory cavitation, both materials exhibit a similar delay before damage accelerates, yet the additively manufactured alloy transitions more readily to significant material removal, with damage paths guided by interlayer interfaces and pores. In chloride solution, corrosion appears highly localized. The build-direction section is the most electrochemically active condition, whereas the scan-plane section approaches the behavior of the wrought bar. Prolonged exposure promotes pit-centered dezincification and the development of zinc-rich corrosion products at pit peripheries, with a deeper affected layer in the additively processed material. Overall, the performance gap is governed primarily by process-induced heterogeneity rather than an intrinsic shortcoming of the alloy. The results offer guidance for the deployment of LPBF CuZn42 in components exposed to cavitation erosion or corrosion in salt water.