Corrosion inhibitor-incorporated layered double hydroxide and sol-gel coating compositions and related processes

US10246594B2 · kind B2 · utility

Assignee

• The Boeing Company · US

Inventors

• Vijaykumar S. Ijeri · Mumbai, IN
• Om Prakash · Kanchinakote, IN
• Stephen P. Gaydos · Chesterfield, US
• Raghavan Subasri · Hyderabad, IN
• Kalidindi Ramachandra Soma Raju · Hyderabad, IN
• Dendi Sreenivas Reddy · Hyderabad, IN

Key dates

• Filing date: Aug 8, 2016
• Grant date: Apr 2, 2019
• Expiry date: Apr 7, 2037

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C2222/20
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A corrosion-resistant coating on an aluminum-containing substrate such as an aluminum substrate, an aluminum alloy substrate (e.g., AA 2024, AA 6061, or AA7075), or other aluminum-containing substrate includes a corrosion inhibitor-incorporated Zn—Al layered double hydroxide (LDH) layer and a sol-gel layer. A zinc salt and a corrosion inhibitor (e.g., a salt of an oxyanion of a transition metal such as a vanadate) is dissolved to form a zinc-corrosion inhibitor solution, and the substrate is immersed in or otherwise contacted with the solution to form the corrosion inhibitor-incorporated Zn—Al LDH layer on the substrate. A sol-gel composition is applied on the corrosion inhibitor-incorporated Zn—Al LDH layer of the substrate to form a sol-gel layer, and the sol-gel layer is cured.