Korrosion von Messing und Bronze durch Ammoniumhalogenide

Corrosion of Brass and Bronze by Ammonium Halides The intermetallic phases brass (Cu/Zn) and bronze (Cu/Sn) are corroded by ammonium fluoride and chloride, NH₄F and NH₄Cl, through selective oxidation of the less noble component zinc and tin, respectively. Copper is recrystallized as cube‐like or tabular single crystals under the respective influence of fluoride and chloride. Zinc and tin are incorporated in complex compounds of which (NH₄)ZnF₃, (NH₄)₂ZnF₄, Zn(NH₃)₂Cl₂ and (NH₄)₃SnF₇ were detected by X‐ray powder diffraction.     

Korrosion

Ohne Zusammenfassung     

Korrosion

Analytical and Bioanalytical Chemistry -     

Korrosion

Ohne Zusammenfassung     

Korrosion

Ohne Zusammenfassung     

Korrosion von Werkstoffen

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Korrosion von Werkstoffen

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Untersuchungen zur Korrosion durch Kunststoffschmelzen an verschiedenen w?rmebehandelten Werkzeugst?hlen mittels ESCA, AES und SIMS

Summary The processing of synthetic material by injection molding machines and extruders produce wear on metal surfaces being in contact with the synthetic material. The corrosion in the melting areas of such machines depends on the chemical and morphological properties of the steel surface. The processing generates chemical changes which can be monitored by means of surface analysis methods. We examined different steels — containing Cr, Mo and V — which were corroded by various melts of synthetic materials. AES, ESCA and SIMS measurements show that some components especially chromium, play a key role for the corrosion process. Corrosion at the surface causes changes of the chemical composition along varying depths (100 – 300 Å). The knowledge of the correlation between chemical changes and surface properties will be helpful for choosing adequate alloys for synthetic material processing machines.