Galvanic corrosion of tungsten coupled with several metals/alloys. Final report for 1994--1997

From an environment perspective, tungsten is a more desirable material than depleted uranium (DU) for penetrator applications. However, the ballistic performance attained by current tungsten (W) alloys is inferior to DU. Recently, advanced tungsten-metal (W-M) composites have been developed to improve their ballistic penetration, but the corrosion properties are unknown and need to be determined. In this work, the galvanic corrosion behavior of W coupled with several selected metals/alloys was investigated. Electrochemical potentiodynamic polarizations and galvanic couplings were employed. The testing was conducted in a 1 wt-% sodium sulfate solution. The selected metals/alloys were: pure W, pure titanium (Ti), Ti 6Al-4V (Ti-6-4), hafnium (Hf), Invar, pure iron (Fe), and brass (CDA 260). The galvanic corrosion of these couples is examined and discussed based on the results from electrochemical tests and visual observations.