Evaluation of single liquid primers with organic sulfur compound for bonding between indirect composite material and silver-palladium-copper-gold alloy.
The purpose of this study was to evaluate the effect of primers on bonding between a silver-palladium-copper-gold alloy and an indirect composite material. Cast disks were air-abraded with alumina, conditioned with one of five primers (Alloy Primer, Luna-Wing Primer, Metal Primer II, Metaltite, M.L. Primer), and bonded with a light-activated indirect composite. Shear bond strengths were determined after 20,000 times of thermocycling. The results showed that four of the primers, except the Luna-Wing Primer, were effective in enhancing the bond strength as compared with the unprimed control group. Of these four primers, Alloy Primer, Metal Primer II, and M.L. Primer exhibited significantly greater bond strengths. It can be concluded that the effectiveness of primers varies considerably according to the organic sulfur compounds added to the solvent, and that care must be taken in selecting priming agents for bonding the composite material and the silver-palladium-copper-gold alloy.
Study on triazine thiols. V. Polymerization of 6‐(4‐vinylbenzyl propyl) amino‐1,3,5‐triazine‐2,4‐dithiol on copper plates and their corrosion resistance
Polymerisation et greffage de groupes vinyliques sur des plaques de cuivre en vue de proteger la surface du cuivre contre la corrosion
Water resistance of resin-bonded joints with time related to alloy surface treatment.
OBJECTIVES
This paper attempts to study the resistance of resin-bonded metallic joints to damage in water with time.


METHODS
Unlike the shear or tensile test, a cleavage test (Double Cantilever Beam test) allows us to follow the crack propagation in water, according to the fracture mechanics concept. Moreover, it is possible to follow the kinetic degradation of the metal/resin interface because this test is not totally destructive to the assembly. We have worked on 18 batches according to the nature of the alloys (Pd, Pd-Ag, Au, Co-Cr and Ni-Cr) and the surface treatment (sandblasting, Silicoater MD, Rocatec, V-Primer). The crack length was measured over a period of 20 days. The results are expressed in terms of adherence energy.


RESULTS
The adherence energy dramatically decreased with time in water. The slope of the regression straight line appears to be a good criterion for evaluating the durability of the alloy/adhesive interface. We have demonstrated the importance of silica coating and, especially, the effectiveness of the Rocatec system upon the degree of hydrolytic degradation, and have shown how the development of cracks depends upon surface treatment.