Title: EFFECTS OF SURFACE PREPARATIONS ON BOND STRENGTH OF MAGNESIUM

The flexural strength of bonded acrylic is tested as a function of panel alignment and bond surface finish. Bond strength was shown to be highly dependent on both parameters with only a narrow range of values yielding a high strength bond. This study was performed for the heavy water-containing acrylic vessel for the Sudbury Neutrino Observatory detector.

Studies of adhesive bonding strength and durability were conducted on three types of engineering plastics. The three substances used were a modified polyethylene oxide, an aromatic polyester liquid crystal polymer, and a poly(amide-imide) polymer. Specimens of these materials were surface treated using physical, chemical, and gas plasma methods prior to adhesive bonding. The adhesives used were two high-temperature curing epoxy adhesives as well as a one-part room temperature setting amide-imide adhesive. The bonded specimens were tested for lap-shear tensile strength after bonding and after increasing periods of exposure to a high temperature and humidity environment. Test results indicate that strongmore » durable bonds are obtained with the proper combination of substrate, surface preparation, and adhesive. The surfaces of these substrate materials were examined with the scanning electron microscope to establish how the surface morphology was affected by the various treatments. 8 refs.« less

No abstract prepared.

This document describes a procedure for determining the flexural bond strength of in situ hollow clay tile bed joints by physical testing of selected joints. This procedure is based on the requirements of ASTM C1072-86. The principal objective of this test is to provide a simple and economical means for the determination of comparative values of flexural bond strength by physical testing of each joint of non-reinforced existing hollow clay tile masonry.