| Abstract Scope |
Decreasing energy consumption in the transportation sector will require weight reduction in new vehicle designs. A viable approach is the substitution of lightweight Al alloys for heavier steels. A significant challenge that adds cost to Al processing is adhesion to forming tool surfaces due to the reactivity of nascent Al liberated via oxide breakup during plastic working. Ceramic tool coatings are often used as adhesion-mitigating materials. To quantify adhesion to pure Al and to guide tool coating selection, the work of adhesion and electronic structure at selected Al/ceramic interfaces were examined with first principles density functional theory. The ceramic tool coating materials include: Al2O3, CrN, TiC, TiN, VC, VN, WC, h-BN, c-BN, graphite, and diamond (unreconstructed, reconstructed, and H-terminated). Of these materials, only one is found to exhibit essentially no adhesion to Al. Finally, we investigated dynamic decomposition of organic additive molecules on clean Al with first principles molecular dynamics. |