Corrosion Resistant Coatings for Uranium and Uranium Alloys

The corrosion of uranium and uranium alloys in many applications is sufficiently fast to require protective coatings. The two major military applications of depleted uranium are kinetic energy penetrators and aircraft counterweights and ballasts. The penetrators are manufactured from depleted uranium with low alloying additions, primarily titanium. In the case of the penetrator, several potential problems are associated with corrosion of the uranium. First, a loss in weight caused by spalling corrosion products could result in a reduction in penetration. Second, corrosion product build-up or loss could cause a reduction in ballistic accuracy due to a shifting in the center of gravity of the penetrator. Third, corrosion product build-up and associated swelling of the encasement could cause the round to jam in the gun. Fourth, the entrance of hydrogen into the metal due to the corrosion reaction could embrittle the penetrator such that it would break-up either upon firing or when hitting the target. The penetrator designs vary considerably; in some, the uranium is completely bare and exposed, while in others it is completely encapsulated.