Banca de QUALIFICAÇÃO: AMANDA REGINA DE SOUZA MACEDO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : AMANDA REGINA DE SOUZA MACEDO
DATA : 27/06/2017
HORA: 14:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

OBTAINING AND CHARACTERIZING A DIATOMY RIBBON THROUGH THE TAPE CASTING PROCESS

PALAVRAS-CHAVES:

Diatomite, Tape Casting, Dielectric Properties.

PÁGINAS: 70
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

Diatomite has a wide variety of applications due to its physical and chemical properties and is widely used as a filter material because of its high porosity. It is a material that also has dielectric properties when in its natural state. In this work, a ceramic tape produced from the diatomite was studied through the tape casting process, to be applied as in dielectric capacitors. The raw material (diatomite) was characterized by particulometry, X-ray diffraction (XRD), X-ray fluorescence (FRX), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) ). The ceramic tape was obtained by preparing a slip with diatomite powder, solvent, dispersant, binder, plasticizer and defoamer; The mixing of the materials was carried out in a ball mill. The rheology test was performed to evaluate the viscosity of the suspension. The slip was glued onto a film and after 24 hours the green ribbon was removed, which was characterized by differential thermal and thermogravimetric analysis (ATD \ ATG), DRX, FRX and MEV. A dielectric ceramic capacitor (prototype) was built with the green tape, in which the electrical capacitance and resistance measurements were performed, and the dielectric constant of the material (diatomite tape) was obtained. The green tape underwent a heat treatment for the removal of organics at a temperature of 600 ° C and a heating rate of 0.5 ° C / min. The sintering was performed at three different temperatures (1000 ° C, 1150 ° C and 1250 ° C), with a heating rate of 5 ° C / min. And 60 min isotherm. It was then characterized by XRD, SEM, and density and porosity measurements. It was observed that the sintered samples presented high porosity in their microstructure, however, for the higher sintering temperatures, there was a reduction of this porosity. The diatomite morphology was maintained for the green and sintered bands, showing its navicular and tubular shape. The presence of pores is due to a typical characteristic of the feedstock (diatomite) used, as well as to the processing parameters, which significantly influenced the dielectric properties of the material, particularly green tape.

MEMBROS DA BANCA:
Presidente - 345842 - UILAME UMBELINO GOMES
Interno - 1149564 - WILSON ACCHAR
Externo à Instituição - ARIADNE DE SOUZA SILVA - UFRN