Banca de DEFESA: AMANDA REGINA DE SOUZA MACEDO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : AMANDA REGINA DE SOUZA MACEDO
DATA : 31/07/2017
HORA: 13:30
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

OBTAINING AND CHARACTERIZING A DIATROMETRIC DIATOMIC TAPE THROUGH THE TAPE CASTING PROCESS

PALAVRAS-CHAVES:

Diatomite, Tape Casting, DielectricProperties.

PÁGINAS: 77
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

Diatomitehas a widevarietyofapplicationsdueto its physicalandchemicalpropertiesandiswidelyused as a filter material becauseof its high porosity. It is a material thatalsohasdielectricpropertieswhenin its naturalstate. In thiswork, a ceramic tape producedfromthediatomitewasstudiedthroughthe tape castingprocess, tobeapplied as in dielectriccapacitors. The raw material (diatomite) wascharacterizedbyparticulometry, X-raydiffraction (XRD), X-rayfluorescence (FRX), scanningelectronmicroscopy (SEM) and Fourier transforminfraredspectroscopy (FTIR) ). The ceramic tape wasobtainedbypreparing a slipwithdiatomitepowder, solvent, dispersant, binder, plasticizeranddefoamer; The mixingofthematerialswascarried out in a ballmill. The rheologytestwasperformedtoevaluatetheviscosityofthesuspension. The slipwasgluedonto a filmandafter 24 hours thegreenribbonwasremoved, whichwascharacterizedbydifferentialthermalandthermogravimetricanalysis (ATD \ ATG), DRX, FRX and MEV. A dielectricceramic capacitor (prototype) wasbuiltwiththegreen tape, in whichtheelectricalcapacitanceandresistancemeasurementswereperformed, andthedielectricconstantofthe material (diatomite tape) wasobtained. The green tape underwent a heattreatment for theremovaloforganicsat a temperatureof 600 ° C and a heating rate of 0.5 ° C / min. The sinteringwasperformedatthreedifferenttemperatures (1000 ° C, 1150 ° C and 1250 ° C), with a heating rate of 5 ° C / min. And 60 min isotherm. It wasthencharacterizedby XRD, SEM, anddensityandporositymeasurements. It wasobservedthatthesinteredsamplespresented high porosity in theirmicrostructure, however, for thehighersinteringtemperatures, therewas a reductionofthisporosity. The diatomitemorphologywasmaintained for thegreenandsinteredbands, showingits navicularand tubular shape. The presenceof pores isdueto a typicalcharacteristicofthefeedstock (diatomite) used, as well as totheprocessingparameters, whichsignificantlyinfluencedthedielectricpropertiesofthe material, particularlygreen tape.

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