Development of an environmentally friendly protective coating for the depleted uranium-0.75wt.% titanium alloy

Effect of alloyed Ti on the microstructure and corrosion characteristics of a U–Ti alloy in a hydrogen environment

“…Recently, Jones [1] observed that hydride growth could be readily initiated at inclusion sites, particularly monocarbides. As pointed out in our previous work [18], the surface of U-Ti alloys is heterogeneous; further, this surface contains some particles that are usually composed of Ti and C, which are also reported elsewhere [26]. These particles behave similarly as carbides in a U metal when these particles are exposed in H 2 .…”

“…These small hydrides reached their final size quickly, and they join together when they encounter some other pits. The final diameters of these hydrides are within a few lm to approximately (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) lm. This phenomenon is similar to the reported preferential hydriding on the grain boundaries of depleted U [6,7].…”

Development of an environmentally friendly protective coating for the depleted uranium–0.75wt.% titanium alloy

“…In the aged coatings, the potential has become ennobled and the corrosion current has dropped by an order of magnitude. The as-made coating has a potentiodynamic polarization curve that is very similar to that of the uncoated DU alloy [4,5] and also displays the same impedance spectra as the uncoated samples. The Bode and the Nyquist plots are shown for the uncoated samples in Figs.…”

“…The samples, 2.5 cm diameter discs cut from a DU-0.75 wt.% Ti alloy (0.75 wt.% Ti, less than 0.2 wt.% 235 U and ∼0.0008 wt.% 234 U, balance is 238 U with various trace impurities), were polished in a contained environment that was nitrogen purged as described earlier [4]. The samples were then degreased with isopropanol and rinsed with deionized water immediately after the polishing steps.…”

“…The presence of airborne uranium corrosion compounds presents environmental and health hazards [2]. In order to reduce the corrosion, studies were undertaken to form an environmentally friendly corrosion resistant coating on the DU-0.75 wt.% Ti alloy [3][4][5]. Protective molybdenum conversion coatings have been formed on the DU-0.75 wt.% Ti alloy and it was found that these coatings only become protective after having been allowed to age for several weeks in an ambient atmosphere.…”