Estudo das propriedades e do comportamento em desgaste abrasivo em microescala do revestimento a base de FeNbC depositado sobre o aço SAE 1020 por aspersão térmica chama a pó

Detalhes bibliográficos
Ano de defesa: 2021
Autor(a) principal: Oliveira, Juliana Souza de
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal do Espírito Santo
BR
Mestrado em Engenharia Mecânica
Centro Tecnológico
UFES
Programa de Pós-Graduação em Engenharia Mecânica
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://repositorio.ufes.br/handle/10/15294
Resumo: Demands for higher performance in industrial applications leads to technological development for wear and corrosion materials protection. The use of superior mechanical and tribological properties coatings on a lower cost substrate is an economically attractive solution. Thermally sprayed coatings stands out for the use of composite materials in high wear resistance systems. At this work, FeNbC coatings deposited on SAE 1020 steel by powder oxyacetylene flame spray process are analyzed. The parameters variation of powder granulometry, spray distance, feed rate and substrate preheating on thermal spraying resulted in nine study conditions. Optical and scanning electron microscopy analyzes showed the coating heterogeneous microstructure, characterized by splats with pores, cracks and oxides between layers. Coatings cross-section Vickers microhardness tests resulted in high hardness, about four times bigger than the steel substrate. Knoop indentations test was used to evaluate the Young’s modulus, which showed the fragile feature coatings. Vickers microindentation tests allowed to evaluate the fracture toughness wich presented values between 1.52 and 2.52 MPa√m. The coating/substrate adhesion and the cohesion between splats were evaluated by coating cross-section scratch test. The thicker coatings also showed greater adhesion. Ball cratering tests with SiO2 abrasive slurry was used to evaluate abrasive wear resistance. Worn sufaces scanning electron microscopy images showed a dominant grooving wear micromechanism. Microindentations at wear grooves suggests a rolling wear secondary micromechanism. Lower hardness coatings also showed the lowest abrasive wear resistance.