UMA APLICAÇÃO DA ANÁLISE DE IMAGENS NA CARACTERIZAÇÃO MICROESTRUTURAL DE CERÂMICAS VARISTORAS

Varistors are very complex polycrystalline ceramic systems containing several dopants and their electrical properties are directly dependent on the chemical composition and on microstructural characteristics, such as grain size, porosity, twins and phase distribution. The aim of this work is to eval...

Full description

Saved in:
Bibliographic Details
Published in:Tecnologia em metalurgia, materiais e mineração materiais e mineração, 2010-01, Vol.6 (3), p.179
Main Authors: Furtado, José Geraldo de M, Dias, Rodrigo, Nóbrega, Maria Cecília de S, Serra, Eduardo Torres
Format: Article
Language:Portuguese
Subjects:
Alloys
Ceramic tools
Ceramics
Chemical composition
Densification
Dispersion
Dopants
Electrical properties
Electronic devices
Energy dispersive X ray spectroscopy
Filtration
Grain boundaries
Image analysis
Image processing
Microstructure
Morphology
Oxides
Phases
Porosity
Rare earth compounds
Scanning electron microscopy
Spectroscopic analysis
Thickness
X-rays
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Varistors are very complex polycrystalline ceramic systems containing several dopants and their electrical properties are directly dependent on the chemical composition and on microstructural characteristics, such as grain size, porosity, twins and phase distribution. The aim of this work is to evaluate, using image analysis tools, the microstructural characteristics of varistor ceramics. The microstructural characterization was made by scanning electron microscopy and energy dispersive X-ray spectroscopy. Microstructural and morphological parameters were obtained by means image analysis techniques based on appropriate filters. Segmentation and binarization methods were used to differentiate grain and grain boundaries properties, as well phase structures. In this study, image processing and measurements have been developed in order to extract the relevant microstructural parameters on the varistor ceramics. It was developed an appropriate filtering and segmentation method for analysis of varistor ceramics to obtain grain and grain boundaries structural and morphological informations. In the case of zinc oxide-based varistors doped with rare-earth oxides it was determined the influence of the intergranular layer former material on the densification degree, the average thickness of the intergranular layers and the average percentage of area occupied by secondary phases.
ISSN:2176-1515
2176-1523
DOI:10.4322/tmm.00603011