Surface treatment

US6521052B2 · kind B2 · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Cheol Park · Grafton, US
• Sharon E. Lowther · Hampton, US
• Terry L. St. Clair · Poquoson, US

Key dates

• Filing date: Feb 9, 2001
• Grant date: Feb 18, 2003
• Expiry date: Feb 9, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C22/78
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A simple surface treatment process is provided which offers a high performance surface for a variety of applications at low cost. This novel surface treatment, which is particularly useful for Ti-6Al-4V alloys, is achieved by forming oxides on the surface with a two-step chemical process and without mechanical abrasion. First, after solvent degreasing, sulfuric acid is used to generate a fresh titanium surface. Next, an alkaline perborate solution is used to form an oxide on the surface. This acid-followed-by-base treatment is cost effective and relatively safe to use in commercial applications. In addition, it is chromium-free, and has been successfully used with a sol-gel coating to afford a strong adhesive bond that exhibits excellent durability after the bonded specimens have been subjected to a harsh 72 hour water boil immersion. Phenylethynyl containing adhesives were used to evaluate this surface treatment with a novel coupling agent containing both trialkoxysilane and phenylethynyl groups.