Metallographic studies of the copper patina formed in the atmosphere
1987; Elsevier BV; Volume: 27; Issue: 7 Linguagem: Inglês
10.1016/0010-938x(87)90048-5
ISSN1879-0496
Autores Tópico(s)Cultural Heritage Materials Analysis
ResumoThe green coating (patina) which forms on copper has been metallurgically investigated by examining 14 samples exposed to the atmosphere for periods of 1–100 years. Various samples in cross-sectioned form are shown to have a layered structure with numerous voids throughout. Oxides and sulfates predominate in the patinas, and small amounts of chlorine and phosphorus can also be found. Extremes in patina growths manifested as color variations are shown to result from variations in grain structure brought about by different heat treatment prior to exposure of the copper to the elements.
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