Banca de QUALIFICAÇÃO: JEFFERSON THADEU DIAS DE OLIVEIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : JEFFERSON THADEU DIAS DE OLIVEIRA
DATA : 10/12/2019
HORA: 13:30
LOCAL: sala 301, 3º andar, Bloco B, Campus SA da Fundação Universidade Federal do ABC, localizada na Avenida dos Estados, 5001, Santa Terezinha, Santo André, SP
TÍTULO:

Development of sealing process for anodized AZ31B magnesium alloy

PÁGINAS: 60
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia Física
ESPECIALIDADE: Corrosão
RESUMO:

High electrochemical activity is a limitation to the widespread use of magnesium and its alloys in engineering applications. Anodization is a possible method to increase the corrosion resistance of magnesium alloys. It consists of an electrolytic oxidation process in which the metallic surface, the anode in the electrolytic cell, is converted into an oxide film that presents corrosion protection ability and functional properties. Sealing of this oxide layer is a highly recommended step to improve the barrier properties of the anodic film. The aim of this project is to develop sealing treatments for the anodized AZ31B magnesium alloy using lanthanum-based aqueous solutions and to evaluate its corrosion resistance ability. The results will be compared with the conventional sealing in boiling water. The anodizing electrolyte was an aqueous solution consisting of a mixture of sodium silicate and sodium hydroxide. The samples were anodized for 5 minutes at a constant current density of 20 mA.cm^-2. Sealing of the anodized layer was carried out in a lanthanum nitrate-based solution, varying treatment time and temperature. The sealed surfaces were characterized by scanning electron microscopy and confocal laser scanning microscopy. The corrosion behavior was assessed by electrochemical impedance spectroscopy and potentiodynamic polarization. In the next steps of the project, the chemical composition of the sealed surfaces will be analyzed by X-ray photoelectron spectroscopy. The partial results allowed identifying the optimum sealing conditions to improve the corrosion protection ability of the anodized film.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1671292 - SYDNEY FERREIRA SANTOS
Membro Titular - Examinador(a) Interno ao Programa - 1925199 - ANIBAL DE ANDRADE MENDES FILHO
Membro Titular - Examinador(a) Interno ao Programa - 1893637 - ALEJANDRO ANDRES ZUNIGA PAEZ
Membro Suplente - Examinador(a) Interno ao Programa - 1646041 - CARLOS TRIVENO RIOS
Membro Suplente - Examinador(a) Externo à Instituição - FERNANDA MARTINS QUEIROZ