Aluminum alloy articles exhibiting improved bond durability and methods of making the same
Disclosed are metal articles and methods of making and processing such metal articles. More particularly, disclosed are aluminum alloy articles exhibiting controllable surface properties, including excellent bond durability. An aluminum alloy article as described herein includes a surface having a concentration of an alloying element, and a coating having a concentration of an element capable of interacting with the alloying element. Also disclosed herein are methods of providing metal articles having excellent bond durability.
1 . A pretreated aluminum alloy article comprising an aluminum alloy:
a first surface portion of the aluminum alloy comprising excess Si, wherein the excess Si is present in the first surface portion of the aluminum alloy in an amount greater than 1.4 wt. %, wherein excess Si content is calculated by subtracting from total Si content the Si needed for Mg 2 Si, which is Mg/1.72, and for an Fe-containing phase, which is Fe/3; and
a surface pretreatment layer consisting essentially of one or more Si-containing compounds,
wherein either one of the first surface portion of the aluminum alloy or the one or more Si-containing compounds comprises O,
wherein Si-O-Si bonding interactions exist between the excess Si present in the first surface portion of the aluminum alloy and the one or more Si-containing compounds present in the surface pretreatment layer, and
wherein the surface pretreatment layer is adhered to the aluminum alloy.
2 . The pretreated aluminum alloy article of claim 1 , wherein the aluminum alloy comprises a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6 xxx series aluminum alloy.
3 . The pretreated aluminum alloy article of claim 1 , wherein the pretreated metal article is an automotive structural part, an aerospace structural part, a transportation structural part, an automotive body part, an aerospace skin panel, a transportation body part, an architectural part, an aesthetic part, an electronics device housing, or a beverage or food container.