Utilização de lama vermelha para oxidação eletrolítica assistida por plasma de diferentes metais

• Ano de defesa: 2021
• Autor(a) principal: Souza, Carime dos Santos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Red mud; Plasma assisted electrolytic oxidation; Carbon steel 1020; Aluzine; Solid waste.; Lama vermelha; Oxidação eletrolítica assistida por plasma; Liga de alumínio 1200; Aço carbono 1020; Aluzinco; Resíduos sólidos; 1200 aluminum alloy
• Link de acesso: http://hdl.handle.net/11449/214723

Within the policy of reducing the amount of industrial and mining waste generated, a good alternative is to develop technologies that enable its reuse. In this scenario, evaluating one of the waste generated in the Sorocaba region linked to mining, the red mud stands out. An alternative is to use residue as a ceramic coating on metals. This work proposes its use, for the production and characterization of protective coatings, on surfaces of different metallic alloys, through the technique of plasma assisted electrolytic oxidation - PEO. Coatings in aluminum alloys 1200, carbon steel 1020 and aluzinc were obtained through PEO using a solution prepared with red mud and distilled water, applying 600 and 500 V potential, using different deposition times and times. The coatings were obtained by MEV, EDS, DRX (except carbon steel), FTIR, Roughness, Wetability, Hardness, Thickness techniques, were evaluated as mechanical properties through the pin-on-disc and corrosion test. The coatings obtained with total red mud in aluminum 1200 showed greater roughness in relation to the coatings obtained with the silt/clay fraction. For the depositions on 1020 carbon steel and aluzinc, the roughness was greater than for the polished substrates. The coatings on 1200 aluminum substrate using total red mud (LVT) and silt/clay fraction (LVA) showed hydrophobic characteristics, while the coatings on 1020 carbon steel and aluzinc were classified as hydrophilic. As for hardness, only the coatings obtained with LVA in aluminum alloy have greater hardness in relation to its substrate. As for the study of mechanical wear, the coatings obtained with LVT and LVA in 1200 aluminum alloy showed an increase in surface resistance and the coatings can be classified as abrasive. Corrosion evaluation shows that for aluminum alloy coatings, damage is greater for those obtained with LVA than for coatings obtained with LVT. For the coatings obtained from 1020 carbon steel, the highest corrosion rates are observed, identifying them as severe. It can be said that the red mud can be applied in the production of coatings on the three types of metals, however, in aluminum alloy and aluzinc, ceramic coatings are obtained which, under certain conditions, improve the properties of the substrates.