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.