Damage analysis of the serious incident that took place on 29 December 2004 on the Mürren‐Birg section of the Schilthorn aerial ropeway identified the cause of failure as hydrogen‐induced stress corrosion cracking. The necessary preconditions for this damage mechanism, which was previously unknown in the aerial ropeway industry, were established by the complex interaction of various ancillary conditions. During periodic rope relocation in 1977, galling occurred between the track rope and a deflection saddle as a result of inadequate lubrication. The friction or galling processes resulted in changes in the grain structure (friction‐induced martensite) as well as scale‐like smearing on the wire surfaces. The formation of friction‐induced martensite results in local stress changes (peak tensile stresses on the surface). Over time, corrosion processes took place in the area of the surface defects under dissociating conditions (absence of air), producing diffusible hydrogen. The hydrogen diffuses preferentially to points of peak stresses and gives rise to embrittlement of the material and intergranular cracks. The results of the investigation were immediately distributed to the licensing authorities and aerial ropeway operators in the form of specially designed training materials to enable appropriate inspections of systems of similar design. Detailed evaluation of this preventive measure is still in progress.

Failures repeatedly occur in the hot dip galvanising of structural steelwork, the appearance of which are directly influenced by the nature of the finishing process and which are often the result of an unexpected interaction between the various parameters and materials involved. The examination of such failures can indicate where the process can be improved in order to avoid future problems.

Glass-bead blasted stainless steel sheets are used in recent time for many applications in architecture or design of machines. If chloride can be accumulated on the surface, glass-bead blasted stainless steel show a worse corrosion behaviour than ground stainless steel. The corrosion behaviour of glass-bead blasted stainless steel is characterised by electrochemical, topographic and roughness investigations. The results of glass-bead blasted stainless steel will be compared with results of other surface treated steels like ground, structure rolled, sand-blasted and electropolished stainless steel. It is shown that not only the roughness parameter Ra has an influence on the corrosion behaviour but also the shape of the valleys and peaks, which are produced during different surface treatments. The investigations lead to advices for the use of these materials in practice.

Different metallic materials, which are in use for building roofs and facades, were exposed to open atmosphere in Dübendorf (Switzerland). The following materials were investigated: copper and zinc with different surface treatment, tinned copper, galvanized steel, aluminium, stainless steel, tinned stainless steel, titanium, and lead. The runoff during rain periods were collected and chemically analysed. It could be shown that copper, zinc and lead release “measurable” amounts of metallic ions and only a small fraction of “particulate” matter. From aluminium, stainless steel and titanium the release was smaller than the detection limit (< 0.01 mg L−1) of the analysis method used. The runoff data will be compared with the corrosion data. The corrosion rate decreases in the course of time whereas the runoff rate shows relatively a constant behaviour.

Within a damage expertise, an examination was performed on three knives by means of fractographic, metallographic, and corrosion chemical characterization methods. The knives were proved to have been manufactured in a proper quality. Apart from showing mechanical damage and tempering colours left behind by regrinding procedures, the damaged knives showed to have undergone a corrosive intercrystalline attacks, which supported knife blade ruptures. Their failure was clearly caused by improper handling conditions and insufficient care.

Copper and zinc are the most abundant facade and roofing materials sensitive for corrosion in Switzerland. For calculating potential material losses of copper and zinc by corrosion-induced runoff, i.e. washed or blown away material, dose-response functions (DRFs) are derived from the results of a Swiss outdoor corrosion exposure programme (Leuenberger-Minger et al., 2002b, Mater. Corros.53, 157–164). The DRFs are also compared with other DRFs available from literature.

Suspended ceilings in indoor swimming pools are safety‐relevant components. As was demonstrated by the collapses of the ceiling of the Uster (CH) indoor swimming pool (1985) and again at Steenwijk (NL, 2001) greater attention has to be paid to selecting suitable materials and inspecting the state of such components. Our findings according to corrosion of metal fastening components of more than 150 indoor swimming pools in Switzerland are reported. The corrosion behaviour of stainless steels and galvanized steels are compared and discussed including newer results from the literature.

Runoff and total corrosion loss for copper and zinc were investigated at seven sites in Switzerland. The exposure sites were chosen near the stations of the National Air Pollution Monitoring Network (NABEL), where climatic and air pollution data are measured. Runoff and corrosion rates were investigated after 0.5, 1, 2 and 4 years of exposure. Runoff rates differ from corrosion rates depending on the material, the exposure time and the sampling site.

Dose-response functions (DRFs) for weathering steel (WTSt 52), copper and zinc were obtained from a four-year exposure programme within Switzerland. Corrosion loss for steel, copper and zinc was investigated at seven sites. The exposure sites were chosen near the stations of the National Air Pollution Monitoring Network (NABEL), where climatic and air pollution data are measured. Corrosion loss was investigated gravimetrically after 1, 2 and 4 years of exposure.The resulting DRFs show a critical contribution of ozone in addition to sulphur dioxide to the corrosion of steel, copper and zinc. The growing demand for environmental protective actions has led to lower atmospheric SO2 levels as a result of the use of cleaner heating oil and sophisticated gas emission controls. This has increased the relative importance of other atmospheric pollutants like ozone or nitrous oxide for the corrosion of metallic materials. (C) 2002 Published by Elsevier Science Ltd.

As part of an investigation into the failure of a cast aluminium candelabrum style street lamp, which toppled over of its own accord, a metallographical examination and chemical analysis of the corrosion products were carried out. The cause of the failure was revealed to be stress corrosion.

Environmental effects on metallic materials are investigated by the combination of a field exposure programme and laboratory exposures. The exposure sites were chosen at locations of the Swiss National Air Pollution Monitoring Network (NABEL) in different regions of Switzerland. Using material loss and the type of corrosion products formed after four years in conjunction with the local climate data, the relevant parameters for the corrosion of the materials investigated can be deduced. Further insights into the mechanism are gained by laboratory exposures carried out in humid air containing single air pollutants (SO2, NO, NO2, O-3, laboratory air). Sulfur dioxide and the time of wetness are playing the most important factors for the corrosion of unalloyed carbon steel, zinc, and hot-dip galvanized steel. In the case of copper, ozone has to be considered in addition. The analysis of the mass of corrosion products retained on the surface of zinc samples showed that in the case of unsheltered specimens ca. 60% of the corroded zinc was lost while for the sheltered samples 90% of the corroded zinc remained on the surface of the specimen. The results of the study can be used for the evalutation of the air protection measures.

As part of an investigation into the failure of a cast aluminium candelabrum style street lamp, which toppled over of its own accord, a metallographical examination and chemical analysis of the corrosion products were carried out. The cause of the failure was revealed to be stress corrosion.

Laboratory exposures of copper, zinc and aluminium were carried out in humid air containing single air pollutants (SO2, NO2, NO, O3) and laboratory air in order to investigate their role in atmospheric corrosion. Realistic pollutant supply rates as normally encountered in outdoor exposures were chosen for the experiments. Some experiments resulted in the formation of corrosion products with morphologies commonly formed during outdoor exposure. The air pollutants sulphur dioxide, nitrogen dioxide and especially ozone play a crucial role in the atmospheric degradation of the materials investigated. Ozone has the strongest effect on the corrosion of copper followed by nitrogen dioxide and sulphur dioxide. Realistic corrosion products such as cuprite (Cu2O), basic copper nitrates and basic copper sulfates were identified in these experiments. The effect of sulphur dioxide exceeds by far the effects of the other air pollutants in the corrosion of zinc. The experiments resulted in the formation of zinc sulphates, which are water-soluble at the test conditions (relative humidity: 90%). Ozone plays a significant role in the corrosion of aluminium, while the effect of sulphur and nitrogen dioxide was considerably smaller. The present work summarises recently discovered effects of the air pollutants mentioned and presents results of a comparative study on the effects of single air pollutants on the corrosion of copper, zinc and aluminium under realistic test conditions. The microstructures of the corroded surfaces were investigated by scanning electron (SEM/EDX) and also partially by Auger electron microscopy (AES). Corrosion products were analysed using X-ray diffraction (XRD) and ion chromatography (IC). Results from gravimetric evaluation are also reported.

The corrosion behavior of different metals commonly used in civil engineering and construction was investigated under outdoor exposure conditions. The exposure sites were chosen at locations of the Swiss National Air Pollution Monitoring Network (NABEL) in different regions of Switzerland, where the concentrations of different air pollutants and climate data are registered continuously. After different exposure times, a set of test specimens is taken back for gravimetric evaluation of material loss and chemical characterization of corrosion products and deposits. Transmission and scanning electron microscopy, X-ray diffraction (XRD), and X-ray fluorescence (XRF) were used to characterize corrosion products. Water soluble compounds on the metal surfaces have also been analyzed quantitatively. First results for the exposure period of six months are presented. They show large differences in corrosion rate and in the amount of corrosive species on the metal surfaces for the different test sites. In some cases a very good correlation to the specific pollution and climate conditions at the particular locations is possible.

The corrosion behavior of different metals commonly used in civil engineering and construction was investigated under outdoor exposure conditions. The exposure sites were chosen at locations of the Swiss National Air Pollution Monitoring Network (NABEL) in different regions of Switzerland, where the concentrations of different air pollutants and climate data are registered continuously. After different exposure times, a set of test specimens is taken back for gravimetric evaluation of material loss and chemical characterization of corrosion products and deposits. Transmission and scanning electron microscopy, X-ray diffraction (XRD), and X-rav fluorescence (XRF) were used to characterize corrosion products. Water soluble compounds on the metal surfaces have also been analyzed quantitatively. First results for the exposure period of six months are presented. They show large differences in corrosion rate and in the amount of corrosive species on the metal surfaces for the different test sites. In some cases a very good correlation to the specific pollution and climate conditions at the particular locations is possible.

Amorphous, 200 nm thin multilayer structures (including films composed of the pure constituents) and homogeneously mixed films, respectively, were prepared by alternating deposition and co-deposition of alumina and zirconia. Subsequent heating of the films showed crystallization temperatures between 850 and 950°C. At 1000°C, the selective crystallization of metastable cubic zirconia was observed. The elastoplastic properties of the amorphous films were examined using ultra-low load indentation tests. The hardness and the Young's modulus of multilayer structures varied linearly with the overall alumina-zirconia composition. Homogeneously mixed films, by contrast, deviated from such a linear relationship. They exhibited a hardness higher than even alumina films and simultaneously a Young's modulus lower than even zirconia films over a wide concentration range. Different proportionalities between hardness and Young's modulus were observed for the multilayer and the homogeneous films. These results indicate that the molecular mixing of the cpnstituents led to an increase of both the yield strength and the maximum elastic tensile strain.

The configurations involved in the spontaneous vitrification of quenched Cr-Ti β-phase alloys were investigated by X-ray diffraction and elastic neutron scattering. The two methods yield complementary information: X-rays are sensitive to the topology whereas neutrons emphasize the chemical fluctuations. The results show the presence of two simultaneous but opposing processes, the formation of CsCl-type chemical short range order on one hand and progressive structural disordering on the other. The latter ultimately leads to amorphization. The probable reason for this behavior is that at the temperature in question only the chromium atoms are mobile.