Banca de DEFESA: FILIPE AUGUSTO DE FARIA CUNHA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FILIPE AUGUSTO DE FARIA CUNHA
DATE: 30/11/2022
TIME: 08:30
LOCAL: Virtual
TITLE:

Study of the behavior of Ni-based superalloys MAR-M247, during isothermal and cyclic oxidation at 1.000 and 1.100 °C, and MAR-M246, conventional and Nb-modified, during cyclic oxidation at 1.100 °C.

KEY WORDS:

Characterization, Oxidation kinetics, MAR-M247, MAR-M246, Isothermal
oxidation, Cyclic oxidation.

PAGES: 183
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia Física
SPECIALTY: Corrosão
SUMMARY:

Superalloys are mainly used because of their exceptional properties, such as mechanical strength and oxidation resistance. The oxidative process is commonly observed in engineering applications and it is usually accentuated under conditions involving high temperatures. These alloys are often used in operations involving high temperatures and stresses, such as gas turbines. This makes the study of oxidation for superalloys relevant. The main objective of this work was to study the oxidation process in the MAR-M247 superalloy, followed by a complementary analysis of the conventional MAR-M246 and Nb-modified MAR-M246 superalloys. MAR-M247 superalloy was exposed to isothermal tests at 1.000 and 1.100 °C for up to 300 hours. This alloy has also been tested cyclically at 1.000 °C for up to 200 cycles and at 1100 °C for up to 219 cycles. The superalloys MAR-M246 (Ta) and MAR-M246 (Nb) were evaluated in relation to cyclic oxidation at 1.100 °C, for up to 219 cycles, in order to study the influence of the replacement of Ta by Nb. The oxidation kinetics and the characterization of the oxidation products were evaluated. The characterization of the samples was performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and optical microscopy (OM). Some of the conclusions obtained in this work are: NiO, Al2O3, TiO2, Co3O4, NiCr2O4 e CoCr2O4 are common oxidation products for MAR-M247; the MAR-M247 alloy proved to be the most resistant to the oxidation process, followed by MAR-M246 and MAR-M246 (Nb), the last one exhibited the lowest resistance among the alloys.

BANKING MEMBERS:
Presidente - 1049564 - ARTUR MARIANO DE SOUSA MALAFAIA
Interno - 1507262 - KURT STRECKER
Externo à Instituição - RENATO BALDAN - UNESP
Externo à Instituição - FREDERICO AUGUSTO PIRES FERNANDES - UFABC