Método de caracterização microestrutural da junção Smba2cu3o7-δ Aço Inoxidável 304l por imageamento

• Ano de defesa: 2017
• Autor(a) principal: Gripa, Victor Luiz
• 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
• Palavras-chave em Português: Ceramic; Superconductors; Grain size; Probability density function; Cerâmica; Supercondutores; Geometria de grãos; Função densidade de probabilidade; Engenharia Mecânica; 621
• Link de acesso: http://repositorio.ufes.br/handle/10/6922

Since superconducting ceramic materials are hard and brittle, it’s limited in technological applications that expose them to electrical and thermal stresses, such as a Ceramic Superconducting Current Limiter. One possible solution to this limitation is the combination of ceramic materials with the properties of metallic materials. With this in mind, the deposition of the SmBa2Cu3O7-δ polycrystalline ceramic was made in a vat produced in AISI 304L stainless steel. The resulting junction was thermally treated by a flash method at 1060 °C. The characterization of the junction was made by X-ray diffraction and scanning electron microscopy (SEM). In addition, a standardized and reproducible method for grain geometry analysis using ImageJ software was developed exclusively for this work. The data obtained by the method were treated statistically in order to show a reduction on the parameters of the grains of all ceramic deposited on the basis of images of some parts of the microstructure by determination of the Probability Density Function (gama, Weibull or normal-logarithm) more appropriate to each case. Although the composite has not been transitioned at temperatures above 77K, a reduction in the grain size of the composite compared to the grain size of the original ceramic could be observed which improves the percolation of the superconducting current in the passage between grains.