The introduction of promising reinforcing elements into the aluminum matrix, such as quasicrystals, opens up new horizons in the creation of materials with improved mechanical properties. Traditional metallurgical methods, due to their availability and relative simplicity, remain an important tool for the production of such composites.
The composite manufacturing process begins with the preparation of a powder mixture comprising aluminum powder and quasi-crystalline particles. It is important to ensure uniform distribution of the reinforcing elements in the matrix, which is achieved by thoroughly mixing the powders using various methods such as ball mill mixing.
The next step is consolidation of the powder mixture. Various methods can be used for this purpose, including hot pressing, extrusion, and injection molding. Hot pressing, in particular, allows for dense blanks with minimal porosity. It is important to control the temperature and pressure during the consolidation process to avoid destruction of the quasi-crystalline structure.
Quasicrystal-reinforced aluminum matrix composites are typically produced by rapid crystallization or powder metallurgy techniques. This study presents a metallic system that forms a microstructure with quasicrystalline Al7Cu2Fe phases and aluminum by casting an alloy of a specific composition and then heat treating it.
The Al85Cu6.75Fe3.375Cr4.875 (in atomic percent) alloy was produced in an arc furnace, annealed, and then characterized using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results demonstrate the feasibility of creating aluminum matrix composites reinforced with quasicrystals using traditional metallurgical manufacturing techniques. This opens new possibilities for the use of quasicrystalline alloys and composite materials.
The resulting composites undergo further processing, including mechanical processing and heat treatment. Mechanical processing allows the product to be given the required shape and size. Heat treatment can be used to improve the mechanical properties of the composite, for example, to relieve internal stress.
The study of the microstructure and mechanical properties of the obtained composites is an important stage in assessing the efficiency of using traditional metallurgical methods. Microstructure analysis allows us to assess the distribution of quasicrystals in the aluminum matrix, as well as the presence of defects such as pores and cracks. Mechanical tests, including tensile, compression and hardness tests, allow us to assess the strength, plasticity and wear resistance of the composite.
Author: Witor Wolf, Claudemiro Bolfarini, Claudio S. Kiminami, Walter J. Botta
Institute: Postgraduate Program in Materials Science and Engineering, Federal University of São Carlos, R. Washington Luis, km 235, São Carlos, São Paulo 13565-905, Brazil, Department of Metallurgy and Materials Science, Federal University of Minas Gerais, Avenida António Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil, Department of Materials Science, Federal University of São Carlos, Rod. Washington Luis, km 235, São Carlos, São Paulo 13565-905, Brazil