Crevice formation

Figure 16. Model In PC based electrolytes, solvent co-intercalation, gas formation and crevice formation in polycrystalline graphite materials are inter-related reactions. In fact, there is a subsequence of reactions (1) PC co-intercalation, (2) gas formation, (3) crevice formation ultimately resulting in exfoliation and macroscopic destruction of graphite [40],...

Feldspars are common aluminosilicate minerals that are present in many different igneous rocks including granites and rhyolites [11], When exposed, these rocks are susceptible to physical and chemical attack. Water, along with the sun, plant roots, and other forces physically attack rock formations causing crevice formation and fracture [3], Water also attacks rocks chemically. Over time, anhydrous aluminosilicate compounds such as those present in igneous minerals react with water to form hydrated species [20], The classic chemical reaction for clay formation involves the decomposition of potash feldspar due to the action of water-containing dissolved C02 to form kaolinite (insoluble) and soluble ionic species (Reaction 1) [14],... 

Figure 11.85. Specimens after end of immersion test with crevice formation, (a)-(c) show specimens 1-3 [120].

Immersion test with crevice formation, no short-circuit/ visual, stereomicroscopy 2 3 3 5 3 3 5 2 1... 

When using plate electrodes it is necessary to consider whether the reverse side should be insulated. This is not necessary in systems with high conductivity and with sufficient distance between the electrode and the cell wall. Insulated plate electrodes produce problems as a result of crevice formation. The best solution is, however, to provide the plate electrode with two counter electrodes situated on both sides of the plate. 

There is a uniform defect density in the pipeline coating. Detachment of the coating and crevice formation must be considered. 

Figure 6.21 Schematic description of the stages of a crevice formation (a) first stage (b) second stage (c) third stage.

In joining of two surfaces, crevice formation and galvanic effects are two major considerations. 

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