Otimização do processo de preparação metalográfica da liga de alumínio AA7075 para análise por difração de elétrons retroespalhados (EBSD)

• Autor(a) principal: Guimarães, Patrick Eduardo Moreira [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155346; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-04-18/000882016.pdf
• topic: Ligas de aluminio; Metalografia; Eletrons - Difração; Aluminum alloys

The metallurgy is considered one of the most important tests to ensure the quality of materials in the manufacturing process and also to develop new alloys. Due to the high sensitivity of the elecrtron diffraction technique (EBSD) requires a flat and unstrained surface. The most common polishes are electrolytic and mechanical polishing with colloidal silica, being only the second used in this work. The main objective is to develop metallographic preparation techniques of AA7075 alloy for analysis of crystallographic texture by electron backscatter diffraction. The league 7XXX class is a treatable alloy heat, that features high mechanical strength and low density, thus being much used in aeronautical applications. The EBSD technique allows crystallographic analysis of a material, ie the determination of the crystal orientation punctually or in specific areas. It is based on the acquisition of diffraction patterns in a scanning electron microscope (SEM), whose analysis coupled to the control of the SEM beam lines or areas of the sample, it is integrated into a computer generating crystallographic orientation maps. The image is processed and then compared with pre-established standards. Metallographic preparation was carried out for 3 processes: automatic rotary polishing, vibratory grinding and polishing by sliding. The automatic rotary polishing showed the best result, because of its flatness and low plastic deformation. XRD was performed to generate data for SEM and EDS library to verify that the chemical composition of the sample was in agreement with the literature, which was in the range specified by the same. Despite problems in the course of working with the software library, necessitating the development of a for performing compared to pre-established standards, it was possible to develop routes with good quality and low cost, ... (Complete abstract click electronic access below)