ADHESIVE BONDING FOR THE HSCT: CHARACTERIZATION AND BOND DURABILITY OF Ti-6Al-4V ADHERENDS

William L. Heard and Dr. John G. Dillard
National Science Foundation and Technology Center:
High Performance Polymeric Adhesive and Composites, and
Department of Chemistry
Virginia Polytechnic Institute and State University
Blacksburg, Virginia

ABSTRACT

Surface characterization and bond durability of anodized Ti-6Al-4V adherends bonded with a high performance polyimide adhesive, LARC TM* -PETI-5, have been investigated. The development of an acceptable surface treatment of Ti-6Al-4V adherends is vital to the construction and performance of the HSCT (high speed civil transport) aircraft. This study focused on the durability of the metal surface preparation and of bonded specimens. Titanium-6Al-4V was anodized in chromic and molybdic acid solutions. Specimens were bonded using supported PETI-5 polyimide adhesive. The durability of bonded wedge specimens was investigated by immersing wedge specimens in boiling water. The crack growth was measured as a function of time and the mode of failure was determined. The mode of failure was determined using surface sensitive analytical techniques. A parallel study of the thermal stability of the surface anodic oxides was also carried out using X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES).

(*TM = trademark; note that at this time html does not support some special characters.)