{"id":113,"date":"2025-08-21T14:52:57","date_gmt":"2025-08-21T12:52:57","guid":{"rendered":"https:\/\/sites.unica.it\/superfici\/?page_id=113"},"modified":"2025-08-21T14:56:13","modified_gmt":"2025-08-21T12:56:13","slug":"ageing-of-brass-alloys","status":"publish","type":"page","link":"https:\/\/sites.unica.it\/superfici\/ageing-of-brass-alloys\/","title":{"rendered":"Ageing of brass alloys"},"content":{"rendered":"\n

The ageing process of brass alloys, the dissolution rate versus<\/em> time, was studied in artificial saliva (pH 7.4) and in a phosphate buffer solution (pH 7). Mechanically polished brass alloys (Zn content 18\u201338 wt%) were exposed for 1, 3 and 16 hours to the solutions open to air at room temperature. The open circuit potential (OCP) and linear polarization resistance (R<\/em>p<\/sub><\/small>) increased asymptotically with ageing time, indicating a decrease of the dissolution rate upon time. In the artificial saliva the corrosion rate decreased from initially 60 \u03bcm per year to 0.5 \u03bcm per year after 16 h of exposure, and alloys with a higher zinc content in the alloy showed higher dissolution rates. In the less aggressive phosphate buffer solution the corrosion rate decreased only by a factor of two. <\/p>\n\n\n\n

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This different reaction mechanism can be interpreted on the basis of the surface film composition determined by X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES): while following the exposure to artificial saliva a thick protective film of CuSCN and zinc phosphate was formed, the film present on the brass alloys was very thin and was made of copper oxide Cu2<\/sub><\/small>O and ZnO.<\/p>\n<\/div><\/div>\n\n\n\n

The thickness and the composition of the surface films formed in the two different electrolytes are essential for the interpretation of the electrochemical results summarized in the diagnostic log Rp vs. OCP plot. <\/p>\n\n\n\n

Publication:<\/strong><\/p>\n\n\n\n

F. Cocco, M. Fantauzzi, B. Elsener, A. Rossi, Dissolution of brass alloys naturally aged in neutral solutions – an electrochemical and surface analytical study<\/strong>,   RSC Advances 6<\/strong> (2016) 90654 – 90665    DOI 10.1039\/C6RA18200C<\/a><\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

The ageing process of brass alloys, the dissolution rate versus time, was studied in artificial saliva (pH 7.4) and in a phosphate buffer solution (pH 7). Mechanically polished brass alloys (Zn content 18\u201338 wt%) were exposed for 1, […]<\/p>\n","protected":false},"author":335,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-113","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/pages\/113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/users\/335"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/comments?post=113"}],"version-history":[{"count":2,"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/pages\/113\/revisions"}],"predecessor-version":[{"id":117,"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/pages\/113\/revisions\/117"}],"wp:attachment":[{"href":"https:\/\/sites.unica.it\/superfici\/wp-json\/wp\/v2\/media?parent=113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}