METAL AND OVERGLAZE SINTERING IN A SINGLE FIRE APPLIED TO THE SPECIAL PARTS INDUSTRY

• Published in: Tecnologia em Metalurgia, Materiais e Mineracao Vol. 12; no. 2; pp. 159 - 166
• Main Authors: Zaccaron, Alexandre, de Souza Nandi, Vitor, Bonomi, Adailton, Fernandes, Paulo
• Format: Journal Article
• Language: English
• Published: Associação Brasileira de Metalurgia, Materiais e Mineração 01.06.2015
• Subjects: Brazil; Drainage; Durability; Firing; Overglaze; Sintering; Single firing; Scratch hardness; Sintering (powder metallurgy); Thermal expansion
• ISSN: 2176-1515; 2176-1523
• DOI: 10.4322/2176-1523.0848

In the present study, the characteristics of sintering of metal and overglaze in a single firing was verified. For that, it was collected 5 samples of overglaze from different glazing companies in the South region of Brazil, which were characterized by chemical analysis, coefficient of linear thermal expansion by dilatometry, and draining button (glaze melt flow) test. Then, the overglazes were applied in the as-received condition and after milling for 5 and 10 minutes; the powders were characterized by particle size distribution analysis. Overglaze layers mixed with gold powder were applied to ceramic plates with mass of 0.5 and 1.0 g, and sintering was performed at four different temperatures (800 degree C, 850 degree C, 900 degree C and 950 degree C) with 60 minutes firing cycle. Finally, the following tests were performed: visual analysis, light microscopy, colorimetry, and Mohs hardness. With the results of this work, samples with brightness and color characteristics close to the standard commercial product produced in multiple firings could be obtained. In the scratch resistance (Mohs hardness), the result was one point above the standard, indicating a better quality and durability of the material.Original Abstract: O presente estudo consistiu em verificar as caracteristicas na sinterizacao de metal e vitrosa em uma unica queima. Para isso foram coletadas 5 amostras de vitrosas de diferentes empresas de colorificios da regiao Sul, que foram caracterizadas por meio de analise quimica, coeficiente de expansao termica linear por dilatometria e ensaio de botao de escorrimento. Em seguida realizou-se a aplicacao das vitrosas em estado de fornecimento e com moagem de 5 e 10 min, sendo os pos caracterizados por meio de determinacao da distribuicao de tamanhos de particulas. As camadas de vitrosas misturadas com po de ouro aplicadas sobre placas ceramicas foram de 0,5 e 1,0 g e a sinterizacao foi realizada em quatro temperaturas diferentes (800[degrees]C, 850[degrees]C, 900[degrees]C e 950[degrees]C) com o ciclo de queima de 60 min. Por fim, foram realizados os ensaios de analise visual, microscopia optica, colorimetria e dureza Mohs. Com os resultados deste trabalho pode-se obter amostras com caracteristicas proximas de cor e brilho relacionadas ao padrao comercial deste produto produzido em multiplas queimas. Ja na resistencia ao risco (dureza Mohs), o resultado apresentou-se um ponto acima do padrao, indicando uma melhor qualidade e durabilidade do material.