The effect of the saliva formulation on brass corrosion. Issue 2 (11th October 2022)

• Record Type: Journal Article
• Authors: Biggio, Deborah; Elsener, Bernhard; Atzei, Davide; Rossi, Antonella; Fantauzzi, Marzia
• Is Part Of: Materials and corrosion. Volume 74:Issue 2(2023)
• Page Start: 269
• Page End: 276
• Publication Date: 2022-10-11
• Subjects: artificial saliva -- brass -- corrosion -- surface films -- XPS; Materials -- Periodicals; Metals -- Periodicals; Corrosion and anti-corrosives -- Periodicals; 620.1122305
• DOI: 10.1002/maco.202213476
• Languages: English
• ISSNs: 0947-5117

Abstract

Abstract: The composition of natural saliva is strongly variable and unstable outside the oral cavity, therefore corrosion tests are usually performed in artificial saliva solutions. In this study the effect of the composition of various saliva solutions on the corrosion behavior of a CuZn37 alloy, exposed for 1, 3, and 16 h to the solutions, is investigated by using electrochemical measurements, optical microscopy, and X‐ray photoelectron spectroscopy (XPS). The solutions investigated in this study are: Darvell, Carter‐Brugirard, and SALMO, selected for their composition that mainly differs in the organic compounds' content. Electrochemical measurements show that the open circuit potential and the polarization resistance increase with exposure time in the solutions, indicating a decrease in the corrosion rate. The corrosion rate (µm/year) in the Darvell solution is found to be two times higher than the other artificial saliva formulations and varies in the order: Darvell > Carter‐Brugirard > SALMO. These data suggest that the presence of different organic compounds might limit the formation of a stable protective surface film as confirmed by XPS surface analyses. Abstract : The corrosion behavior of brass in contact with artificial saliva solutions is influenced by the presence of organic compounds in the formulation. CuZn37 exposed to a solution containing ligands (Darvell) showed the highest corrosion rate compared to solutions where urea and some amino acids were the only inorganic constituents (Carter‐Brugirard and SALMO). The presence of ligands in the solution hinders the formation of zinc‐phosphate, which protects the brass from further corrosion.