Failure modes/mechanisms adhesion loss

The interfacial chemistry of corrosion-induced failure has also been studied for coatings with relatively poor resistance to water (poor wet adhesion) for these materials, the corrosion-induced failure typically involved little chemical change, but appeared to involve the same displacement mechanism observed for hvunidity induced adhesion loss (19). XPS spectra showing this mode of failure are reproduced in Figure 1 for this coating, essentially identical spectra were obtained from all surfaces analyzed, independent of test conditions. 

The possible delamination modes are (i) loss of adhesion at paint/phosphate interface, (ii) within phosphate layer due to mechanical fracture (iii) due to dissolution of phosphate (iv) dissolution of coating (v) mechanical failure at coating/steel interface. 

The propensity for image collapse depends on the width and proximity of the features, its aspect ratio, the substrate surface, and the mechanical properties of the imaged resist. Two characteristic failure modes have been identified deformation, where fracture occurs within the resist structure, and adhesion loss, where the resist feature separates from the substrate at their interface. Low surface-tension rinse liquids [in the extreme, supercritical fluids (101)] and the use of rigid and highly adhesive resists reduce the frequency of image collapse. 

There are two main modes of failure that have been linked to acetal rolling bearings. These modes can occur in conjunction with each other or by themselves. These modes of failure are the result of wear. Wear occurs by the following mechanisms adhesion between the smooth steel ball and the polymer raceway surface and material loss associated with fatigue pits on the surface. Generally the steel balls are so smooth that there is little wear caused by surface asperities abrading the polymer surface. 

Wear is the process of physical loss of material. In sliding contacts this can arise from a number of processes in order of relative importance they are adhesion, abrasion, corrosion and contact fatigue. Wear occurs because of local mechanical failure of highly stressed interfacial zones and the mode of failure is influenced by environmental factors. 

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