Banca de DEFESA: PEDRO ALIGHIERY SILVA DE ARAUJO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : PEDRO ALIGHIERY SILVA DE ARAUJO
DATE: 15/12/2021
TIME: 09:00
LOCAL: Remoto: meet.google.com/oci-mtev-idm
TITLE:

EFFECT OF ADDING FROM COFFEE ASH RESIDUE AND CeO2 ON PHASE TRANSFORMATION IN CORDIERITE

KEY WORDS:

cordierite, sintering, microstructure.

PAGES: 106
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

Cordierite is one of the compounds in the MgO-Al₂O₃-SiO₂ system that has the lowest thermal expansion coefficient among inorganic oxides. Despite this advantage, which results in high resistance to thermal shock, monophasic cordierite is difficult to prepare, and the existence of secondary phases increases its thermal expansion coefficient. Therefore, the elimination of undesirable phases is one of the key points in the preparation of cordierite ceramics with low thermal expansion. Many sintering additives (TiO₂,CaO, Li₂O, Na₂O, Fe₂O₃, ZnO, e ZrO₂) have been used to stimulate the sintering of cordierite precursor powders and modify the microstructures and properties of ceramics. Unfortunately, many of these sintering additives increase the thermal expansion coefficient of the obtained ceramics. In this context, this doctoral work proposes to study the effects of different levels of rare earth oxide (CeO₂) and coffee ash residue on the elimination of secondary phases, sintering mechanisms, microstructure and properties of cordierite-based ceramics. The samples will be obtained by reactive sintering (in a conventional oven) of stoichiometric mixtures of magnesium, aluminum and silicon oxides (reference sample) from natural raw materials rich in these elements. Both K₂O, contained in the ash residue from the coffee husk, and CeO₂, in low amounts, can stimulate the reaction of cristobalite and spinel to form cordierite.

BANKING MEMBERS:
Presidente - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externa à Instituição - CAROLINE GOMES MOURA
Externo à Instituição - DANIEL ARAÚJO DE MACEDO - UFPB
Externo à Instituição - JOÃO PAULO DE FREITAS GRILO - UA
Externo à Instituição - RICARDO PEIXOTO SUASSUNA DUTRA - UFPB