Metal matrix composite materials (MMCs) have attracted considerable attention due to their unique combination of strength, rigidity, and wear resistance. Reinforcement of a metal matrix with quasicrystal (QC) particles is a promising approach to creating materials with improved tribological properties. The cold spraying method (CSM) is an effective method for producing MMCs, which avoids high temperatures and preserves the structure of the reinforcing particles.
The matrix was aluminum alloy AA5056. The reinforcing component was particles of quasicrystalline Al-Cu-Fe alloy. Composite coatings were obtained by cold spraying on substrates made of AISI 304 steel. Microstructural studies were carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Tribological tests were carried out on a tribometer using the pin-on-disk scheme under dry friction conditions.
In this paper, the application of metal matrix composites (MMC) by cold gas-dynamic spraying is investigated. A mixture of AlCuFeB quasi-crystal and tin bronze powders was used to create MMC reinforced with quasi-crystalline inclusions. The effect of adding quasi-crystalline particles on the coating formation process, its structure and microhardness was studied. Tribological tests using the “ball-on-disk” scheme were carried out to assess the effect of the hardening phase on the wear resistance of the coating. The results showed that the introduction of quasi-crystalline particles led to a decrease in porosity and an increase in the microhardness of the coating. At the same time, a decrease in the friction coefficient was observed, but the wear rate increased. Wear mechanisms based on the analysis of the microstructure and microhardness of the coatings are proposed.
Quasicrystalline materials are characterized by a unique atomic structure, which determines their special physical, chemical and mechanical properties, such as low surface energy, high hardness, low friction coefficient and resistance to wear and corrosion. The mechanical properties of quasicrystals are close to those of brittle ceramics or intermetallics, which limits their use as structural materials. However, quasicrystals can be used as a reinforcing phase in composites or to create protective coatings. Thermal spraying methods, due to their flexibility and simplicity, are preferred for obtaining quasicrystalline coatings. Numerous studies have been devoted to the study of the microstructure and properties of such coatings. However, when using traditional thermal spraying methods, undesirable phase transformations of quasicrystals often occur due to high temperatures.
Cold spray is a low-temperature coating process in which particles are accelerated by a Laval nozzle. The coating is formed by plastic deformation of the particles upon impact with the substrate. Cold spray has attracted much attention as a method for producing high-quality metallic coatings. This method can also be used to deposit MMC coatings with improved physical and mechanical properties. In this study, mixtures of AlCuFeB quasicrystals and bronze were cold sprayed to obtain MMC coatings reinforced with quasicrystals. The effect of AlCuFeB content on the coating performance and the relationship between the structure and properties of the composite coatings were studied. Particular attention was paid to the tribological behavior of the coatings and its relationship with the microstructure and mechanical properties.
Microstructural analysis showed uniform distribution of KK particles in the aluminum matrix. Adhesion between KK particles and the matrix was high, which ensured efficient load transfer. Tribological tests revealed a significant reduction in the coefficient of friction and wear of composite coatings compared to pure aluminum alloy. Increased wear resistance of KMM is due to the high hardness of KK particles, which prevent plastic deformation of the matrix and reduce the intensity of abrasive wear.
Author: Xueping Guo, Jingfeng Chen, Hongliang Yu, Hanlin Liao, Christian Coddet
Institute: Marine Engineering College, Jimei University, Xiamen 361021, P.R. China, Fujian Provincial Key Laboratory of Shipbuilding and Ocean Engineering, Xiamen 361021, P.R. China, IRTES-LERMPS (Laboratory of Research and Development in Materials, Processes and Surfaces) – UTBM (University of Technology of Belfort-Montbéliard), Cévenans, Belfort, 90010, France