REVIEW OF SURFACE PRETREATMENTS FOR TITANIUM-ALLOYS

Many treatments to enhance the adhesion to titanium have been studied, especially with respect to their ability to improve the durability of bonded joints. This review examines the effectiveness of a diverse range of treatments in many durability studies and using a variety of tests. The review also identifies 23 techniques that have been used to examine the surfaces of pretreated titanium alloy. These range from complex and costly ultra-high vacuum based surface analytical techniques, such as X-ray photoelectron spectroscopy, to those which are more simple and commonly available, such as contact angles. Overall, the most effective methods are sodium hydroxide and chromic acid anodizing. The recently developed plasma spray treatment is showing much promise.