Banca de QUALIFICAÇÃO: MARCELO DE MATOS MACEDO
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.STUDENT : MARCELO DE MATOS MACEDO
DATE: 13/04/2023
TIME: 14:00
LOCAL: Campus Santo André
TITLE:
Characterization of the tribocorrosion behavior of an austenitic surgical stainless steel in physiological solution
PAGES: 85
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia Física
SPECIALTY: Corrosão
SUMMARY:
Implantable Metallic biomedical devices that play a structural role in the orthopedic field, such as prostheses or fixture devices are subject to a combination of wear and corrosion effects. The simultaneous action of these phenomena is defined as tribocorrosion. The tribocorrosion behavior of surgical stainless steels depends on several parameters such as the normal load and the electrochemical potential to which the metallic material is exposed. In the present work, the surgical austenitic stainless steel ASTM F-139 was subject to tribocorrosion tests in phosphate buffered solution (PBS). The objective was to investigate the effect of the normal load and the electrochemical potential on the tribocorrosion behavior of the ASTM F-139 steel. Additionally, the motivation of this work was to assess the correlation between the passive film composition and the tribocorrosion behavior of the steel. In this respect, wear tests were conducted in a pin-on-disc tribometer, using 5 N, 10 N and 20 N as normal loads. During the tribocorrosion tests, the samples were concomitantly polarized at different potentials: -100 mV versus the open circuit potential, +200 mVAg/AgCl and +700 mVAg/AgCl. These conditions were defined based on preliminary potentiodynamic polarization tests. The tribocorrosion tests were also conducted at the open circuit potential for comparison purposes. Coefficient of friction versus sliding distance curves were acquired, as well as potential versus (at the open circuit condition) or current density versus time curves (for the tests conducted with steel under anodic or cathodic polarization). The results revealed an increase of the current density with the applied potential, independently of the normal load employed in the tribocorrosion tests. In the same regard, by increasing the normal load, the current density was raised too. The wear volume was determined by confocal laser scanning microscopy, being proportional to the current density measured during the tribocorrosion tests.
COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 2604737 - EVERALDO CARLOS VENANCIO
Membro Titular - Examinador(a) Interno ao Programa - 3068039 - MOHAMMAD MASOUMI
Membro Titular - Examinador(a) Externo à Instituição - RONALDO CÂMARA COZZA - FEI
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