Aluminum Matrix Research Articles

Improving mechanical properties and electrical conductivity of Al-Cu-Mg matrix composites by GNPs and sc additions

To enhance the mechanical properties and electrical conductivity of Al-Cu-Mg-based composites, aluminum matrix composites containing scandium (Sc) and graphene nanoplatelets (GNPs) were fabricated by means of stepwise ball milling, vacuum hot pressing sintering, and hot rolling techniques. When Sc and GNPs were incorporated at concentrations of 0.1 wt% and 0.2 wt% respectively, the resultant composites demonstrated a maximum tensile strength of 326.81 MPa, an elongation of 3.2%, an electrical conductivity of 46.95% IACS, and a hardness of 112.96 HV. In comparison with the 2024 aluminum alloy matrix, enhancements of 39%, 255%, 51% and 51.21% were witnessed in tensile strength, elongation, electrical conductivity, and hardness respectively. These improvements can be primarily ascribed to the addition of Sc, which facilitated the precipitation of solute atoms and enhanced the interfacial bonding between the GNPs and the matrix, as well as the remarkable heterogeneous layered microstructure induced by the incorporation of GNPs. This study presents a feasible approach to concurrently enhance the strength and electrical conductivity of composites through the combined addition of Sc and GNPs.

Steel grid-reinforced aluminum matrix composite prepared via wire-based friction stir additive manufacturing

ABSTRACT Grid-reinforced metal matrix composites featuring tailorable mechanical properties pose significant challenges to additive manufacturing due to its co-controlling reinforcement structure and interfacial formation issues. Here, a dense steel grid-reinforced aluminum matrix composite was successfully prepared by wire-based friction stir additive manufacturing. No internal defects, like porosity, grid breakage, or interface cracking, were detected, and the reinforcing grids kept a predefined orientation without deviation. A strong interfacial bonding between the deposited layers and the grid was achieved due to sufficient matrix material flow and diffusion behaviour induced by severe plastic deformation. Compared to pure aluminum, the ultimate tensile strength and flexural strength of the as-deposited composite increased by 27.1% and 41.8%, without loss of ductility, by incorporating a 12.3 vt.% of the steel grid. This work provides an efficient approach to fabricating large-scale metal matrix composites reinforced with other high-performance continuous grid, such as metal fibre and carbon fibre grid.

Experimental study on milling mechanism and surface quality of Mg2Si/Al composites

Mg2Si/Al composites are widely used in aerospace and automotive lightweight applications due to their excellent structural properties, such as superior specific stiffness, specific strength, and wear resistance. The removal mechanism of Mg2Si/Al composites is explored by establishing a finite element milling simulation model. A three-factor, four-level milling experiment based on the orthogonal experimental method is conducted to illustrate the patterns of the effects of milling parameters and surface defects on surface quality. Suitable milling parameters are successfully optimized by predictive modeling and experimental validation methods. The results show that the removal of Mg2Si/Al composites is mainly characterized by plastic deformation of the aluminum matrix and brittle fracture, crushing, bulging, and pulling out of Mg2Si particles.

Microstructures and Mechanical Properties of Al Matrix Composites Reinforced with TiO2 and Graphitic Carbon Nitride

The scattering of reinforcement plays a crucial role in the microstructure and properties of metal matrix composites. In this study, an aluminum matrix composite (AMC) was reinforced by 10 wt% TiO2 (Al-10TiO2), with an average particle size of a submicron, combined with a different content of graphitic carbon nitride (g-C3N4), which was fabricated by shift-speed ball milling (SSBM) combined with multi-pass friction stir processing (FSP). In addition to the high hardness of TiO2, g-C3N4 has functional groups to promote in situ reactions. SSBM improves the distribution of reinforcement, refines grain size, and reduces the structural destruction of g-C3N4. The in situ reaction was achieved after multi-pass FSP at a high rotational speed and low travel speeds, which can promote uniform dispersion and grain refinement. Moreover, the g-C3N4 shows the efficient enhancement of strength while maintaining the elongation of AMC. Because the exfoliation of g-C3N4 under the effect of processing reduces the agglomeration of TiO2, boosts the flattening of Al, and enhances interface integration with the base metal. In situ phases can reduce the generation of coarse phases and improve interfacial bonding ability to enhance mechanical properties. The maximum tensile strength has been found at about 172.5 MPa in the Al-10TiO2 containing 1 wt% g-C3N4, which was enhanced by 34% compared to that of the Al-10TiO2. The tensile strength increases when the g-C3N4 content increases from 0 to 1 wt%, but then reduces with a further increase of content. The hardness was increased by 50.2%, 60.2%, and 35% with a g-C3N4 content of 0.5, 1, and 2 wt% compared to AMCs without reinforcement, respectively. According to the test, the enhancement mechanism is mainly attributed to Orowan, grain refinement strengthening, and load transfer of scattered reinforcement. In summary, the utilization of hybrid reinforcements successfully enhances the microstructure and mechanical properties.

An Initial Study of Ultra High Performance Concrete as Reusable Mold Material for Aluminum Casting.

The initial investigation evaluates the feasibility of ultra high performance concrete (UHPC) as a material for reusable molds in aluminum casting. Two specific UHPC formulations were investigated: one based on ordinary Portland cement (OPC) and another utilizing alkali-activated materials (AAM). The study focused on investigating the surface through roughness measurements and the thermal durability through repeated casting cycles. The thermal stability of the molds was investigated by thermogravimetric analysis, mercury intrusion porosimetry, crack segmentation, optical microscopy, and electron microscopy. Results indicate that molds fabricated from AAM-UHPC exhibit relatively better performance in terms of maintaining structural integrity and surface quality over repeated uses. AAM-UHPC molds were able to withstand up to ten casting cycles with acceptable surface degradation and no significant failure, while OPC-UHPC molds exhibited a faster degradation under similar conditions. Microstructural changes and the interaction of UHPC materials with molten aluminum were investigated, highlighting the low adhesion and defect formation. Additionally, the molds demonstrated sound casting quality, with a grain size comparable to that achieved using traditional steel molds (~ 90 µm), underscoring the potential of UHPC materials for enhancing casting quality and efficiency. The study concludes that UHPC, particularly with alkali-activated formulations, shows promise for low-pressure casting environments.

Influence of the graphene incorporation on nanostructure and thermal properties of the laser powder bed fusion processed AlSi12 matrix composites

The successful fabrication and implementation of graphene-reinforced aluminum (Al) matrix composites (AMCs) have been obstructed by the undesirable graphene-Al reactions during their casting or inability of complex part manufacturing through powder metallurgy techniques. The emergence of the laser powder bed fusion (L-PBF) process with extremely short melt duration and almost no limitations in terms of the manufacturing of intricate features has renewed the interests for fabrication of graphene-reinforced AMCs. In this study, the influence of graphene incorporation into AlSi12 on L-PBF processability and defect formation is studied. The specific heat capacity, coefficient of thermal expansion, thermal diffusivity and thermal conductivity of composites were compared to those of the monolithic AlSi12 alloy. Microstructure-thermal properties relationship was studied through transmission electron microscopy (TEM), high-resolution TEM (HRTEM), electron backscatter diffraction (EBSD), electron dispersive spectroscopy (EDS) and Raman spectroscopy. This study provides valuable insights into (i) the chance of survival of graphene, (ii) possibility of graphene changing into other forms of carbon, and (iii) graphene-Al reactions during the L-PBF process. It was found that most of the graphene/graphite particles transformed into Al4C3. Among the survived carbon material, it appears they are more disordered than the initial graphene/graphite, though highly ordered ones with almost no defects were also detected. Thermal expansion measurements showed that the coefficient of thermal expansion decreased from 27.5×10-6/˚C for AlSi12 to 25.3×10-6/˚C for AlSi12-0.25Gr and 25.5×10-6/˚C for AlSi12-0.5Gr. Regarding thermal conductivity, in the case of AlSi12-0.5Gr, it either matched or was lower than that of pure AlSi12 within the tested temperature range. In contrast, AlSi12-0.25Gr exhibited higher thermal conductivity than AlSi12 in the temperature range of 150-350 ˚C.

High-strength aluminum matrix composites with strong bonding interfaces via in-situ amorphous alumina and plainification strategy

Silicon carbide particle (SiCp) reinforced aluminum matrix composites have potential applications for components under severe service conditions. However, their performance is commonly limited by challenges such as insufficient interfacial bonding strength, agglomeration and brittle interfacial reaction products. In this paper, the ultra-fine grained aluminum and in-situ formed amorphous alumina were fabricated, and the as-formed powder metallurgy SiCp/Al composites achieved excellent properties, with a high yield strength of 471 MPa and an ultimate tensile strength of 505 MPa, respectively. We systematically investigated the structures of the amorphous alumina, which bonds the SiCp and matrix together, improving the interfacial bonding strength and simultaneously suppressing the interfacial reactions. Notably, the proposed fabrication method is suitable for economic production of large-scale components and applicable for aluminum matrix composites with other types of reinforcements.

Wettability and interfacial reactions in Al–mg–Si/SiC and Al–mg–Si/SiO2 systems

The wettability of reinforcing materials by matrix alloy is essential for the successful fabrication of high-performance metal matrix composites. This study investigates the wetting behavior of Al–Mg–Si alloys (Mg: 3–7 wt%, Si: 9–15 wt%) on SiC and SiO2 substrates, providing crucial insights for developing SiC-reinforced aluminum matrix composites. Using a dispensed sessile drop method in an Ar–10 %H2 atmosphere, we systematically examined the influence of alloy composition and temperature on wettability. A key finding is that reducing Si content and increasing temperature significantly enhance wettability in the Al–Mg–Si/SiC system by promoting the formation of Al4C3. In contrast, for the Al–Mg–Si/SiO2 system, increasing Mg content primarily improves initial wettability, while the effect of Si content is less significant. Importantly, this study challenges the conventional understanding of SiC pre-oxidation treatment, demonstrating that its primary role is to control Al4C3 formation rather than directly enhance wettability. These results provide a deeper understanding of the complex interplay among alloying elements, temperature, and interfacial reactions in governing wettability. Furthermore, they offer valuable strategies for process optimization and theoretical guidance for fabricating SiC-reinforced aluminum matrix composites with enhanced properties.

Unveiling single-press channel die bonding for nanostructured multi-layer aluminum matrix composite reinforced with copper nanopowder

Unveiling single-press channel die bonding for nanostructured multi-layer aluminum matrix composite reinforced with copper nanopowder

Tribological characterization of high entropy alloy particles reinforced aluminum matrix composites at room and cryogenic temperatures

Tribological characterization of high entropy alloy particles reinforced aluminum matrix composites at room and cryogenic temperatures

Application of Conversion Coatings on Aluminum Matrix Composites for Corrosion Protection

Application of Conversion Coatings on Aluminum Matrix Composites for Corrosion Protection

Preparation and property enhancement of SiC particle-reinforced aluminum matrix composites based on Micro-arc Oxidation

Aluminum matrix composites (AMC) is a powerful material that responds to the needs of modern science. It is characterized by high specific strength and good wear resistance. Micro-arc Oxidation (MAO) is a surface modification technology that generates a dense ceramic layer in-situ on the surface of a metallic material to improve the material properties. In this study, AMC was prepared by powder metallurgy (PM) technique by adding SiC reinforcing particles in Al matrix, and then the AMC was treated with MAO. The mechanical properties of the samples are evaluated by metal bending test as well as hardness tester. The wear and corrosion resistance of the samples was evaluated by tribological tests as well as electrochemical tests. The test results showed that the AMC prepared by adding SiC particles increased the ultimate flexural strength by 1.5 times to 2117N and the hardness by 1.6 times to 57.6 HV1.0. For the friction performance, the width of the wear marks was reduced by 40.29% and the depth by 71.79%, and for the corrosion resistance, the corrosion current was reduced by 70.21%. The MAO treatment provides effective protection for the AMC, and the coating provides a physical barrier that further enhances AMC performance. The bending resistance has been increased by 1.2 times to 2571N and the hardness by 1.5 times to 86.1 HV1.0. For the friction performance, the width of the wear marks was reduced by 24.06% and the depth by 46.15%, and for the corrosion resistance, the corrosion current was reduced by 25.11%. Surface modification of AMC improves the service life and application range of AMC, which is expected to promote the development of marine transportation and shipbuilding industry.

Heterogeneous configuration induced strengthening in aluminum matrix composites via exciting back stress

Heterogeneous configuration induced strengthening in aluminum matrix composites via exciting back stress

Mechanical property and fracture characteristics of carbon fiber reinforced aluminum matrix composites prepared by friction stir welding

Mechanical property and fracture characteristics of carbon fiber reinforced aluminum matrix composites prepared by friction stir welding

Interfacial structure and strengthening mechanisms of NiO-coated graphene reinforced aluminum matrix composites

Interfacial structure and strengthening mechanisms of NiO-coated graphene reinforced aluminum matrix composites

Endowing a superior synergy of strength and ductility to aluminum matrix composite by dual-structured reinforcement and matrix

Endowing a superior synergy of strength and ductility to aluminum matrix composite by dual-structured reinforcement and matrix

Effect of Pin Length and Compression Force in Double Side Friction Stir Welding on Tensile Strength of AA1100

Friction Stir Welding (FSW) is solid state welding without additives and does not produce pollution. There are two FSW welding methods, namely single side (FSW) and double side (DFSW). The FSW process in previous studies using aluminum materials, especially AA 1100 type, has not obtained optimum joint strength. Therefore, it is necessary to conduct a research study on improving the quality of tensile strength of welding results using the DFSW method on AA1100. The purpose of this study is to determine the effect of variations in pin length and compressive force on the maximum tensile strength of the results of Double Side Friction Stir Welding Aluminum Alloy 1100 welding joints. The method used in this research is experimental. The welding process uses Double Side Friction Stir Welding, by varying two independent variables namely pin length 1.5 mm, 2 mm, 2.5 mm and compressive force 30 kg, 35 kg, 40 kg, 45 kg. The controlled variables used include travel speed (10 mm/min), heating temperature (250℃), shoulder diameter (25 mm), heating plate width (10 mm), and Aluminum AA1100 plate thickness (3.5 mm), with butt joint type welding. The data analysis used is Factorial Design of Experiment (DOE). The results of this study indicate that pin length and compressive force affect the tensile strength of AA1100 material welds. The maximum tensile strength value of DFSW welding results is 90.16 MPa or 80.5% of the tensile strength of the parent material. The maximum tensile strength value was obtained from the interaction of 2 mm pin length and 45 kg compressive force.

Influence of Varying Particle Size on Mechanical & Tribological Properties of A356-Al2O3 Metal Matrix Composites

MMCs represent a new generation of engineering materials in which a strong ceramic reinforcement is incorporated into a metal matrix to improve its properties including specific strength, specific stiffness, wear, corrosion resistance and elastic modulus. Aluminium oxide and silicon carbide powders in the form of fibers and particulates are commonly used as reinforcements in MMCs and the addition of these reinforcements to aluminum alloys has been the subject of a considerable amount of research work. Aluminum oxide and silicon carbide reinforced aluminum alloy matrix composites are applied in the automotive and aircraft where the tribological properties of these materials are considered important. Therefore, the development of aluminum matrix composites is receiving considerable emphasis in meeting the requirements of various industries. An economical way of producing metal matrix composite is the incorporation of the particles into the liquid metal and casting which leads to improvement in strength over the unreinforced alloy. Addition of particulate reinforcement improves stiffness, strength and tribological properties. Particle size also influences the uniformity of distribution of reinforcement in the matrix. Smaller the particle size, higher will be the agglomerate content in the composite structure. Particle also directly influences the porosity content in the composite structure.The purpose of research in Tribology is understandably the minimization of losses resulting from friction and wear at all levels of technology where the rubbing of surfaces is involved. The present work is a small attempt made to study the influence of reinforcement particulate size on the mechanical and tribological characteristics of Al-Al2O3p composites.

Experimental Analysis of Tribological Properties of Aluminium 6061-Al2O3- TiO2 MMC

Composite materials have gained significant prominence in modern engineering due to their superior properties such as high strength-to-weight ratio, wear resistance, and adaptability in design. This research paper focuses on the development and application of aluminum matrix composites (AMCs) reinforced with Al2O3 and TiO2 particulates, which offer enhanced mechanical, thermal, and tribological properties. The study investigates the historical evolution, material characteristics, and manufacturing techniques of metal matrix composites (MMCs) while emphasizing their increasing use in automotive, aerospace, and other industrial applications. Particular attention is given to the role of Al2O3 and TiO2 reinforcements in improving wear resistance and other tribological properties of aluminum alloys. This work underscores the necessity of integrating innovative materials and processes to meet the demands of lightweight, high-performance, and cost-effective solutions in the engineering domain.

Structural and Mechanical Characterization of Aluminum Matrix Nanocomposites Reinforced with SiC and Al2O3 Nanoparticles

Structural and Mechanical Characterization of Aluminum Matrix Nanocomposites Reinforced with SiC and Al2O3 Nanoparticles