Лако-красочные материалы — производство

The assembly technique does influence the final strength of the joint, since especially cryogenic fitting determines an appreciable decay of the adhesive shear strength, even if the components are assembled with interference. The negative effect of heating at +180°C is less severe. Moreover, the shear strength of cylindrical joints reinforced with strong anaerobic adhesive increases with coupling pressure. In fact, comparing the performances of slip fit joints with those of interference fit joints, both reinforced with adhesive and assembled by shrink fit and cryogenic fit, interference fitted joints systematically overperform clearance fit joints in terms of adhesive shear strength. In the light of the results shown above, in practical applications, where heating is always associated with interference, it is expected that the beneficial effect of contact pressure could counterbalance the negative effect of heating. Press fit joints deserve particular attention, because they show a slightly lower shear strength than slip fit ones assembled at R. T. Lower results are observed on press fit joints with adhesive since the adhesive is stripped away from the mating surfaces during the assembling while the beneficial effect of coupling pressure increases the performances of the remaining adhesive; the overall performance of the joint is, therefore, comparable to that of slip fit joints reinforced with adhesive. As an extension of the present work, the effect of the ratio between the coupling length and the coupling diameter on the adhesive performances will be investigated in the future.