Corrosion and Fatigue Behavior of Boeing Space, Intelligence, and Weapons Systems Laser Powder Fusion Built Scalmalloy® in 5% NaCl

This paper presents the results of a preliminary investigation into the corrosion resistance of laser powder bed fusion (LPBF)-produced Scalmalloy® specimens built by Boeing Space, Intelligence, and Weapons Systems (BSI&WS). The specimens were first exposed to a 5% NaCl salt fog test at 35°C, and a comparison was made with prior tests on the aluminum alloy AA7050-T7451. The AA7050-T7451 alloy was chosen since it is widely used in fixed-wing aircraft, rotary-wing aircraft, and in space structures. This preliminary study reveals that BSI&WS LPBF-built Scalmalloy® is significantly more resistant to corrosion pitting than AA7050-T7451. These prior exposed (Scalmalloy®) specimens were then fatigued tested, and it was shown that exposure for 28 days to a 5% salt spray fog environment at 35°C did not reduce the durability of the specimens. As such, this study, when taken in conjunction with the authors' previous report on the exceptional damage tolerance of Scalmalloy®, reveals that the BIS&WS LPBF Scalmalloy® is particularly attractive for use on a range of both fixed- and rotary-wing military aircraft. It also reinforces the potential for BSI&WS LPBF Scalmalloy® to be used in building parts for attritable aircraft/drones.