Aluminum matrix composites (AMCs) reinforced with quasicrystalline particles represent a promising class of materials due to the combination of the lightness of aluminum and the high hardness and wear resistance of quasi-crystals. This paper investigates the structure and properties of AMCs obtained by powder metallurgy using quasi-crystalline Al–Cu–Fe powder as a reinforcing phase.
The morphology and distribution of quasicrystalline particles in the aluminum matrix have a significant effect on the mechanical properties of the composite. Optimization of powder mixing and compaction parameters allows achieving a uniform distribution of reinforcing particles and minimizing the porosity of the material. Thermal treatment of the composite improves adhesion between the matrix and the reinforcing phase, which leads to increased strength and plasticity of the material.
Using vacuum hot pressing, aluminum matrix composites were fabricated utilizing elemental aluminum powder and atomized Al65Cu20Fe15 particles. These Al65Cu20Fe15 particles, which were generally spherical, comprised icosahedral quasicrystalline dendrites (or cells) alongside a cubic τ-AlCu(Fe) phase found in the spaces between the dendrites. Composites were produced with varying concentrations of reinforcing particles (20, 40, and 60 wt%). The composites achieved approximately 99% density and exhibited strong adhesion between the Al65Cu20Fe15 particles and the aluminum matrix. The phase makeup of the atomized particles remained stable after consolidation for composites containing 20% and 40% reinforcement. However, in the composite with 60% Al65Cu20Fe15, Al2Cu precipitates developed at the interfaces between the Al and Al65Cu20Fe15, as well as within the matrix itself. As the proportion of reinforcement increased, both the hardness and compressive strength of the composite also increased. With 60% Al65Cu20Fe15 particles, the hardness reached 173 HV0.5, and the compressive strength reached 370 MPa. The coefficient friction fluctuated marginally between 0.5 and 0.7, depending on the composite’s specific composition.
Studies of the microhardness and wear resistance of KAM have shown a significant improvement in these characteristics compared to pure aluminum. The introduction of quasi-crystalline particles into the aluminum matrix effectively prevents plastic deformation and reduces the friction coefficient of the material. The results obtained indicate the prospects for using KAM reinforced with quasi-crystalline Al-Cu-Fe particles in various areas of technology where a combination of lightness, high hardness and wear resistance is required.
Author: L. Lityńska-Dobrzyńska, J. Dutkiewicz, K. Stan-Głowińska, W. Wajda, L. Dembinski, C. Langlade, C. Coddet
Institute: Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 30-059 Krakow, Reymonta 25, Poland, Belfort-Montbéliard University of Technology, Cévenants, 90010, Belfort, France