Análise e determinação da microestrutura e propriedades mecânicas do magnésio puro e sua liga EZ33 submetidos ao processamento por ECAP

Abstract

Since the International Conference on Magnesium Alloys and their Applications, 1998 made in Wolfsburg, the innovative industry’s interest in magnesium alloys has been sparked, being exponentially explored for having better mechanical properties with low density in comparison with other metals, making them widely qualified for structural components on automobilists, aerospatial, biomedicine industries, and so on. The present monograph pursues to improve the mechanical properties of the pure magnesium and its alloy EZ33A through the ECAP technique, crucially aiming for, posteriorly, being used as a structural material, due to its wide applicability and excellent mechanical resistance. The ECAP process have been made using a die with process parameters such as internal channel of 120o and utilizing the Bc route (90o anticlockwise each pass) with the following extrusion sequence conditions: 4 passes at 300oC, 4 passes at 250oC and condition M (1 pass at 300oC, 1 pass at 275oC, 1 pass at 250oC and 1 pass at 225oC), with a pressing speed of 5 mm/min. Then, the following analysis was made: microstructure, grain size and hardness. The alloy showed promising results, presenting higher values in its mechanical properties, mainly on M condition, increasing approximately 15% in hardness. The microstructure revealed the diminishing of about 57 times on grain size. The pure Mg showed better enhancement in hardness, increasing about 32%, but less increasing in grain size, reducing approximately 37 times its size. Hence, the magnesium alloys processed by ECAP are considerably optimized in their mechanical and microstructural properties, contributing to higher quality applications.