Coatings continued behaviour

Electrode. Preparation and Behaviour of Continuously Deposited Mercury Coatings and Applications to Stripping Analysis. Anal Chem. 33, 1201 (1961). 

Series of as coated, coated/peened, as well as uncoalcd, specimens were oxidised in flowing laboratory air at three temperatures. The effectiveness of FeCrAlY coatings on the oxidation behaviour of Ti3Al was examined at 800°C, while the corresponding influence onTiAl oxidation was investigated at both 900°C and 1000°C. All the specimens were contained in alumina crucibles and were cycled to room temperature after each successive oxidation period. Exposures were continued for cumulative times of 1000 h at 800°C, 775 h at 900°C and 75 h at 1000°C. After defined times the extent of the oxygen uptakes, and where appropriate, also of spallation were determined gravi-mctrically. ... 

Polyurethanes continue to be one of the most versatile of all polymers, finding applications in foams (flexible, rigid, and in-between), elastomers, coatings, sealants, adhesives, paints, textiles, and films. This volume presents some of the major advances in polyurethanes, both from the materials and research side of things as well as processing and applications, and includes studies on foams (additives, vacuum panel applications, blowing and processing), elastomers, adhesion behaviour and new urethane raw materials. 

There is extensive literature on the corrosion behaviour of hot-dip galvanised steel pipes in cold water. In an experiment lasting 3 months on hot-dip galvanised N D 20 steel pipes in the types of water shown in Table 23 at a continuous flow rate of 0.12 m/s, it was found that the corrosion rate depends on the flow rate and the pH [42]. From theoretical considerations, this result is interpreted as follows a virtually stationary state is established in the three-phase system of metal/surface coating/ water, in which the transportation of Zn(OH) ions from the surface of the coating into the water by diffusion is the rate-determining factor. 

The final class of behaviour in oil - - water + surfactant systems is the formation of bicontinuous liquids. In an oil-swollen micelle or o/w microemulsion, the oil is clearly inside the surfactant aggregate, and when it is swollen beyond its limit, bulk excess oil will be observed. Likewise in w/o emulsions, the system can lake up only so much water within the surfactant-coated droplets. But there is also a third class of microemulsions in which neither oil nor water can be regarded as inside or outside of the aggregates. These are referred to as bicontinuous (or more properly tricontinuous) liquids, in which the surfactant forms a flexible monolayer within the liquid separating oil from water microdomains, but without enclosing either. Thus both liquids, as well as the surfactant film, are continuous throughout the liquid, as depicted schematically in Figure 7. 

This unusual behaviour is not only applicable in aqueous electrolytes. Cu-Zn alloys deposited from ionic liquids have also shown galvanic corrosion (Zhu and Hussey, 2001). Metal redox reactions in these systems are very reversible and the electrolyte does not contain dissolved oxygen. This means that metal protection by passivation in solution cannot occur. In addition, many of the coatings obtained in ionic liquids are nanoporous and the electrolyte is in contact with the metallic material, leading to continued corrosion. 

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