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| Author(s): |
João Matheus Rugeri Murdiga
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2021-12-06 |
| Examining board members: |
Eduardo Bellini Ferreira;
Eliria Maria de Jesus Agnolon Pallone;
Joao Gustavo Pereira da Silva
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| Advisor: | Eduardo Bellini Ferreira; Claudio Jose Magon |
| Abstract | |
 The high temperatures and time intervals required for the sintering of ceramic materials have strengthened the research for cheaper alternative processes, such as time reduction by applying an electric field. The application of an electric field during the sintering of polycrystalline ceramic materials has been studied for years, but only recently has it been tested with powdered glass compacts. One approach is called Flash Sintering, which uses a strong electric field to foment rapid sintering by passing current through the sample and overheating by the Joule effect. However, several aspects of applying the technique to powdered glass compacts need to be better understood, such as what is the function of each glass oxide in the process, the influence of chemical composition, the relationship between Flash and simultaneous crystallization. This work was successful by developing an artificial intelligence software based on the Canny and Gaussian Thresholding algorithms for the detection of the specimen, enabling the Frame-to-Frame calculation of the specimen retraction during the Flash Sintering experiments with glasses. The Cluster model was also programmed, this model can estimate the sintering behavior of vitreous materials through viscous flow, and when the results are compared with the previous software, it can calculate the heating rates of the specimen. A model based on several physical processes was developed to simulate Flash, and the result was compared to experimental results, showing a remarkable similarity with the real world. Finally, sintering experiments were executed out with and without an electric field in two compositions in the Lithia-Silica system, with lithium disilicate as the main composition. These experiments were used to validate the computational results and were able to prove the efficiency of the software developed and the mathematical modeling of the process. (AU) | |
| FAPESP's process: | 19/13742-1 - Study of the electrical factors effects on the sintering and crystallization of glasses in the Li2O-SiO2 system |
| Grantee: | João Matheus Rugeri Murdiga |
| Support Opportunities: | Scholarships in Brazil - Master |