Improved corrosion resistance of nickel-aluminum bronze by electron beam powder bed fusion

Abstract

The corrosion resistance of nickel-aluminum bronze (NAB) by electron beam powder bed fusion (EB-PBF) from different-size feeding particles is investigated in neutral 3.5 wt% NaCl solutions. Uniformly-distributed precipitates are observed in the samples at the microscale. The βˊ phase that suffered from corrosion preferentially in conventional as-casting NAB is not observed in the EB-PBF NAB. Typically, the corrosion resistance of EB-PBF NAB built from middle-size particles is improved by 1.35 times that of as-casting NAB. This results from a collective effect of high relative density and uniformly-distributed precipitates, which mitigates selective phase corrosion and promotes the formation of corrosion products with uniform thickness.