Advanced Composites with Aluminum Alloys Matrix and Their Fabrication Processes

This chapter introduces advanced aluminum alloy matrix composites and their manufacturing processes. In the beginning, the state of the art is characterized and the general characteristics of aluminum and its practical applications are presented, starting with the history of aluminum. The current approximate distribution of bauxite resources in the world and the production of bauxite and alumina in the leading countries of the world, as well as the production of primary and secondary aluminum and the range of aluminum end products, are presented. Aluminum alloys intended for plastic deformation and castings, and composite materials in general and with a matrix of aluminum alloys in particular, have been characterized in general. Against this background, a detailed review of the results of the Author’s own research included in numerous projects and own publications on advanced composite materials, their production technology, their structure, and properties were done. The range of aluminum alloy matrices of composite materials was adequately characterized, which include AlSi12, AlSi7Mg0.3, AlMg1SiCu, AlMg3, AlMg5, and AlMg9, respectively. Composite materials tested in terms of manufacturing technology include three groups. The first group includes gas pressure infiltration with liquid aluminum alloys of suitably formed porous preforms. Porous frameworks as a reinforcement for pressure-infiltrated composite materials with a matrix of aluminum alloys are produced by three methods. Al2O3 powder with the addition of 30–50% carbon fibers is uniaxially pressed, sintered, and heated to thermally degrade the carbon fibers and create the required pore sizes. In the second case, the ceramic porous skeleton is produced with the use of halloysite nanotubes HNTs by mechanical milling, press consolidation, and sintering. A third method is SLS selective laser sintering using titanium powders. Another group of manufacturing technologies is the mechanical synthesis of the mixture of AlMg1SiCu aluminum alloy powder and respectively, halloysite nanotubes HNTs in a volume fraction from 5 to 15% or multi-wall carbon nanotubes MWCNTs in a volume fraction from 0.5 to 5%, and subsequent consolidation involving plastic deformation. The third group of analyzed materials concerns composite surface layers on substrates of aluminum alloys produced by laser feathering of WC/W2C or SiC carbides. The structure and properties of the mentioned composite materials with aluminum alloys matrices are described in detail. The chapter summary provides final remarks on the importance of advanced aluminum alloy composite materials in industrial development. The importance of particular groups of engineering materials in the history and the development of the methodology for the selection of engineering materials, including the current stage of Materials 4.0, was emphasized. The importance of material design in engineering design is emphasized. Concepts of the development of societies were presented: Society 5.0 and Industry 4.0. The own concept of a holistic model of the extended Industry 4.0 was presented, taking into account advanced engineering materials and technological processes. Particular attention was paid to the importance of advanced composite materials with an aluminum alloy matrix in the context of the current stage of Industry 4.0 of the industrial revolution. Growth in the production of aluminum, its alloys, and composites with its matrix was compared with that of steel. Despite the 30 times less production, aluminum is important due to its lower density. The challenges posed by the development in the Industry 4.0 stage, including the expectations of the automotive and aviation industry, force constant progress in the development of new materials with the participation of aluminum, including the composite materials with an aluminum alloy matrix presented in this chapter.

Study of the Protection of Aluminum Alloy Surfaces by a Graphene-Modified Fluorocarbon Anticorrosive Coating

Graphene-modified anticorrosion coatings have become a hot spot in the field of metal protection due to the large-scale promotion of aluminum alloys, which are prone to corrosion in marine and atmospheric environments. The protection of aluminum alloy surfaces by a graphene-modified anticorrosive coating was explored in this study by applying a graphene-modified anticorrosive coating to an aluminum alloy surface to test its resistance to corrosion. Dispersion-treated reduced graphene oxide (rGO) was used to modify the epoxy resin and fluorocarbon resin. It was found, by using a scanning electron microscopy (SEM) and the microstructure of the coating made by the Raman Spectroscopy Institute, that the addition of rGO could effectively improve the porosity of the epoxy primer, and the electrochemical workstation was able to resist the graphene-modified anticorrosive coating. The corrosion performance was quickly characterized, the polarization curve and the AC impedance curve were fitted, and it was found that the self-corrosion current density ( J corr ) of the graphene-modified anticorrosive coating was the smallest ( 1.190 × 10 − 7 A / c m 2 ) when 0.6% of rGO was added; the impedance modulus ( ∣ Z ∣ ) was the largest (104), the capacitive reactance arc radius was the largest, and the coating resistance was the largest after fitting (15517 Ω). When 0.8% of rGO was added, the dispersion coefficient was large, and it had a good physical insulation performance. The main reason for the reduction of the corrosion resistance was that the agglomeration of rGO made the aluminum alloy matrix and the external corrosive environment form a highly conductive circuit, thereby accelerating the corrosion of the aluminum alloy matrix.

Mechanical and Tribological Behaviors of WAl12 Reinforced 2024 Aluminum Alloy Matrix Composites

WAl12 reinforced 2024 aluminum alloy matrix composites were prepared by powder metallurgy with tungsten particles and W50Al50 alloy particles. The effects of WAl12 on the mechanical properties of 2024 aluminum alloy composites at room temperature and high temperature were studied, and the friction behavior was characterized. The results show that intermetallic WAl12 phase forms in the composite by 2024 aluminum alloy and tungsten. The mechanical properties and friction behavior can be improved by the formation of intermetallic WAl12 phase. The tensile strength of 2024 aluminum alloy at room temperature and 180 °C can be improved by adding tungsten less than 1.5 at.%. Adding 2.0 at.% tungsten can reduce the friction coefficient by 20 % and the scratch width by 40 %. The tensile fracture surface of the sample was analyzed by scanning electron microscopy (SEM), indicating that WAl12 intermetallic phase is closely connected with the aluminum matrix.