Improving Adhesion at the Alumina/Zinc Interface by Stainless Steel Buffers

Abstract

The weak interaction between zinc and alumina is responsible for a poor performance of anti-corrosive galvanic zinc coatings on modern advanced high strength steels. In this context, we report a theoretical study on the eect of realistic multi-component metal buers on the adhesion strength of a model-alumina(0001)jzinc interface. Relying on results of ab initio calculations on relevant individual oxidejoxide, oxidejmetal, and metaljmetal interfaces (separation and interface energies), we determine by Monte Carlo simulations the thermodynamically preferred sequence of components in a multicomponent buer, as a function of buer composition and oxygen conditions. We nd that stainless steel buers considerably enhance the overall strength of the aluminajzinc interface. Most importantly, we show that a partial oxidation of multi-component buers, which is unavoidable under realistic conditions, does not degrade their performance. This advantageous property relies on the separation of metal and oxide components in the buer and on the resulting suppression of weakly interacting oxidejzinc, and moderately strong aluminajmetal interfaces. More generally, owing to the possibility of selective oxidation and component segregation, multi-component buers appear as promising solutions for adhesion improvement at weakly interacting metaljoxide interfaces.

Structural, electronic and adhesion characteristics of zinc/silica interfaces: ab initio study on zinc/β-cristobalite

“…Before concluding, let us note that the overall pattern of zinc interaction at various terminations of silica shows clear similarities with zinc interaction at the α-alumina(0001) surfaces 44 . This suggests that, similarly to the case of alumina, adhesion improvement of zinc/silica interfaces may require the presence of interfacial buffers made of more reactive elements [45][46][47] . However, we stress that surface siloxane rings, which are a structural peculiarity of the non-polar silica surfaces, may require specific treatment to break them.…”

Atomic and electronic structure of an epitaxial Nb2O3 honeycomb monolayer on Au(111)

“…, and E (Au) are the total energies of the oxide-covered slab, a freestanding fully relaxed oxide layer, and the bare gold slab, respectively. The calculated adhesion energy is 2.34 J/m 2 (4.2 eV per Nb 2 O 3 formula unit or 14.6 eV/nm 2 ), typical of strongly interacting metal/oxide interfaces or other honeycomb transition metal oxides on Au(111) [24,40]. This number can be decomposed into two contributions, namely the elastic energy necessary to constrain the lattice parameter of the freestanding honeycomb monolayer to that of the gold substrate (−1.8 eV) and the oxide-metal interaction energy gained when bringing the constrained oxide film into contact with the Au(111) surface (6.0 eV).…”

Theoretical study of metal/silica interfaces: Ti, Fe, Cr and Ni on β-cristobalite

“…One alternative path may rely on using interfacial buffers composed of more reactive metals. Indeed, in the superficially similar case of alumina/zinc interfaces, we have previously shown that early transition metal 38 or stainless steel 39 buffers can significantly enhance adhesion resulting in cohesive cleavage within the zinc deposit. However, the similarity between the two systems is limited.…”