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Conceção, Produção e Validação Experimental de Micro Sondas de Correntes Induzidas Customizadas
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Os Ensaios Não Destrutivos (END) por Correntes Induzidas (CI) permitem determinar
características do material e detetar a presença de defeitos superficiais e subsuperficiais que
podem ser prejudiciais à integridade estrutural em peças produzidas em materiais condutores
de eletricidade. Apesar de ser uma técnica comum e com muitos anos de experiência acumulada,
existem algumas condições onde persistem dificuldades, como é o caso da deteção de micro
defeitos em componentes de reduzida dimensão ou com difícil acesso.
O objetivo deste trabalho foi conceber, simular numericamente, produzir e validar
experimentalmente diferentes configurações das sondas de CI para: deteção de micro defeitos
para cordões brasados a laser e deteção de defeitos em limas de Endodontia. Outro objetivo
consistiu em desenvolver e aplicar melhorias numa mesa XY de alta resolução para inspeção
automatizada permitindo, por exemplo, o mapeamento de condutividades de um componente
com elevada resolução.
Foram simuladas numericamente, produzidas e caraterizadas sondas com diferentes
geometrias, configurações e parâmetros. No total foram produzidas 19 sondas de CI que
permitiram avaliar a importância de diferentes parâmetros no processo de inspeção.
Os resultados demostraram o potencial das sondas helicoidais cilíndricas na inspeção de
cordões brasados a laser: sondas com diferentes parâmetros mostraram-se capazes de detetar
defeitos superficiais e subsuperficiais. Para a inspeção das limas endodônticas foram testadas
as configurações desenvolvidas sendo que a sonda toroidal montada em modo bridge
diferencial demonstrou ser capaz de detetar um defeito artificial na lima.
Non-Destructive Testing (NDT) by Eddy Currents (EC) allows the determination of material characteristics and the detection of surface and subsurface defects that can be prejudicial to the structural integrity of pieces made of electrically conductive materials. Despite being a common technique with many years of accumulated experience, there are some conditions where difficulties persist, such as the detection of micro defects in small components or with difficult access. The objective of this work was to design, numerically simulate, produce and experimentally validate different configurations of EC probes for: detection of micro defects on laser-brazed joints and detection of defects in Endodontic files. Another objective was to develop and apply improvements to a high resolution XY scanning device for automated inspection, allowing conductivity mapping with high resolution. Numerically simulated, produced, and characterized probes with different geometries, configurations, and parameters. In total, 19 EC probes were produced which allowed to aess the importance of different parameters for the inspection process. The results demonstrated the potential of helicoidal cylindrical probes in the inspection of laser-brazed joints: probes with different parameters proved to be capable of detecting surface and subsurface defects. For the inspection of endodontic files, the developed configurations were tested, and one demonstrated to be able to detect an artificial defect in the file.
Non-Destructive Testing (NDT) by Eddy Currents (EC) allows the determination of material characteristics and the detection of surface and subsurface defects that can be prejudicial to the structural integrity of pieces made of electrically conductive materials. Despite being a common technique with many years of accumulated experience, there are some conditions where difficulties persist, such as the detection of micro defects in small components or with difficult access. The objective of this work was to design, numerically simulate, produce and experimentally validate different configurations of EC probes for: detection of micro defects on laser-brazed joints and detection of defects in Endodontic files. Another objective was to develop and apply improvements to a high resolution XY scanning device for automated inspection, allowing conductivity mapping with high resolution. Numerically simulated, produced, and characterized probes with different geometries, configurations, and parameters. In total, 19 EC probes were produced which allowed to aess the importance of different parameters for the inspection process. The results demonstrated the potential of helicoidal cylindrical probes in the inspection of laser-brazed joints: probes with different parameters proved to be capable of detecting surface and subsurface defects. For the inspection of endodontic files, the developed configurations were tested, and one demonstrated to be able to detect an artificial defect in the file.
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Palavras-chave
Ensaios Não Destrutivos (END) Correntes Induzidas (CI) Micro Sonda Micro Defeito Limas de Endodontia Cordão Brasado a Laser