A STUDY OF TITANIUM SURFACE PRETREATMENTS FOR BONDING WITH POLYIMIDE AND EPOXY ADHESIVES

Adhesive bond durability depends on the properties of the adhesive, th e surface preparation, and the primer used. Surface pretreatment is ne cessary in order to substitute the preexisting weak oxide layer on the metal surface with a more stable one. Currently, chromic acid anodizi ng is the most widely used pretreatment on titanium surfaces prior to bonding. Among the chemical treatments, Pasa jell 107, Turco 5578, and alkaline peroxide etching are widely known. The importance of a good surface pretreatment can not be overstated in applications where high performance and durability are critical. It is the objective of this s tudy to examine the conventional surface pretreatments for titanium to gether with some more recently developed treatments. Among these newer pretreatments, two sol/gel methods were investigated. Single lap shea rs and floating roller peel samples were prepared using epoxy and poly imide adhesives.