Evaluation of the Alkaline Peroxide Pre-Bond Surface Treatment for Titanium.

摘要

Alkaline peroxide and Pasajell 107 pre-bond treatments were evaluated with three different adhesives in an effort to increase the durability of bonded titanium structures. Lap shear, wedge and stress durability specimens were prepared and pre-bond surfaces were evaluated after environmental exposures up to six months. Titanium-to-titanium results showed the alkaline peroxide treatment exhibited higher lap shear strengths than the Pasajell 107 treatment at both RT and 180 deg F. When the adhesives were used without primer, the Pasajell 107 treatment exhibited slightly higher lap shear strengths. The majority of titanium-to-graphite lap shear coupons failed in the composite, confirming the lower interlaminar strength of the composite when compared to the adhesive bonds. Wedge tests were conducted on panels that were cleaned and then stored for 0 month, 3 months and 6 months at elevated temperature and humidity. The alkaline peroxide treated specimens exhibited markedly higher durability than the Pasajell 107 treated specimens. Overall the alkaline peroxide treated specimens demonstrated comparable initial strength to the Pasajell 107 cleaned specimens, but when exposed for various periods of time to elevated temperature and humidity, the alkaline peroxide treated specimens provided a significantly more stable surface and thus a more durable bond.