Banca de QUALIFICAÇÃO: PAULA LIMA BRAGA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : PAULA LIMA BRAGA
DATA : 30/08/2022
HORA: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/carlos-118
TÍTULO:

Development of anodizing treatment of the ZK60A alloy in alkaline electrolyte containing graphene oxide and characterization of its corrosion behavior

PÁGINAS: 120
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia Física
ESPECIALIDADE: Corrosão
RESUMO:

The anodization treatment of the ZK60A alloy was developed in an alkaline electrolyte, containing silicate and graphene oxide (GO). The effect of anodizing current density, treatment time and GO concentration in the electrolyte on the corrosion behavior of the ZK60A alloy was assessed. During the anodizing treatment, the time and the current density applied were monitored in order to study and compare their effects on the structure and corrosion resistance of the oxide films. For this purpose, microstructural characterization techniques were used, such as confocal laser scanning microscopy, which allowed the observation of changes in the topographic features and surface roughness of the ZK60A alloy, with increasing anodization time. Scanning electron microscopy allowed the observation of: surface morphology, crack formation and thickness of the oxide films.EDS (energy dispersive X-ray spectroscopy) analysis revealed the incorporation of silicon in the anodized layer. The electrochemical behavior was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization curves in 3.5 wt.% NaCl solution at room temperature. The results showed that all anodic films increased the corrosion resistance of the ZK60A alloy. The higher the anodizing current, the greater the film thickness. However, the increase of the anodizing time was not directly related to a corresponding increase of film thickness and corrosion resistance.The samples that showed the best performance and electrochemical stability were the SiB-20-20 and SiB-30-30 films. Various concentrations of graphene oxide in the electrolyte were added to the electrolyte in order to study their effects on the corrosion resistance of the anodized layers. The SiBGO-20-20-1 film shifted the corrosion potential to more positive values and an increased the passivity region. However, the corrosion current density was not significantly altered with respect toto the SiB-20-20 film.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1646041 - CARLOS TRIVENO RIOS
Membro Titular - Examinador(a) Interno ao Programa - 3068039 - MOHAMMAD MASOUMI
Membro Titular - Examinador(a) Externo à Instituição - FERNANDA MARTINS QUEIROZ - SENAI/CETIQT
Membro Suplente - Examinador(a) Interno ao Programa - 1925199 - ANIBAL DE ANDRADE MENDES FILHO
Membro Suplente - Examinador(a) Externo ao Programa - 2297395 - FREDERICO AUGUSTO PIRES FERNANDES