Banca de DEFESA: FELIPE FERNANDES BARBOSA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : FELIPE FERNANDES BARBOSA
DATA : 30/07/2018
HORA: 14:00
LOCAL: Auditório do NUPPRAR
TÍTULO:

Synthesis of the FeCo alloy encapsulated in carbon filaments with chemical strength from the dehydrogenation of ethylbenzene

PALAVRAS-CHAVES:

FeCo alloy, organized carbon, ethylbenzene dehydrogenation and alloys encapsulation.

PÁGINAS: 83
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

The catalytic dehydrogenation of ethylbenzene was used to study the nature of deposited carbon and to verify the formation of organized structures in the form of FeCo magnetic alloys encapsulated in carbon filaments via chemical vapor deposition (CVD). The reducing environment from the dehydrogenation (H2 generated in situ) was used to synthesize an FeCo alloy from the metal oxide. The program is organized in four different temperatures (700, 650, 600 and 550 °C), in the times of 2h and 4h. X-ray diffraction (XRD), programmed temperature reduction (TPR), thermogravimetric analysis (TGA), scanning electron microscopy (FEG-MEV) and X-ray dispersive energy (EDS) were characterized. , vibration sample magnitude (VSM), Raman, transmission electron microscopy (TEM) and gas phase (GC) chromatography. The diffractograms indicate an FeCo alloy formation and a presence of crystalline carbon. The H2-TPR profiles confirm that the alloy can be formed at the reaction temperature from 370 °C. Since the images elaborated by FEG-SEM and TEM indicated a formation of carbon filaments and a FeCo alloy favor the growth of the carbon structurally organized. The images also confirm that the alloy encapsulates the force against the acid. The ratio of the Raman D and G bands confirms that carbon growth on an FeCo alloy is favored at higher temperatures. Chromatograms indicate that the filaments were formed from the methane and/or ethene generated in situ in the reaction, which were seen were not identified. The magnetic properties were confirmed by the VSM, a variable according to the reaction time and temperature. The saturation magnetization of a direct relationship with the crystallite size of the alloy.

MEMBROS DA BANCA:
Externo à Instituição - FABIO GARCIA PENHA - IFRN
Presidente - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externo à Instituição - RAFAEL SARAIVA NUNES - UFAL
Externo ao Programa - 2087667 - TIAGO PINHEIRO BRAGA