Aluminum Alloy Matrix Research Articles

Synergistic enhancement of strength and plasticity of SiCp/Al composites by designing and controlling SiCp@MgAl2O4 core-shell micro-interfaces

Building a superior balance of strength and plasticity inversion is a challenge in the development of aluminum matrix composites reinforced with medium volume fraction SiC particles. In this study, we reported an interface design strategy to simultaneously enhance the strength and plasticity of 30 vol% SiCp/Al composite by in-situ generating SiC@MgAl2O4 core-shell micro-nanostructures. The results showed that a uniform MgAl2O4 shell layer with a thickness of ∼300 nm was formed when the Mg content was 4.0 wt%. The MgAl2O4 shell layer formed abundant coherent interfaces with both SiC particles and aluminum alloy matrix, exhibiting powerful interfacial bonding strength. During the deformation process, the effective transmission of load and the delay of fracture achieved a synergistic improvement in both strength and plasticity.

Ni-based coating on 5083 aluminum alloy with Cu-Ni interlayer fabricated by ultra-high-speed laser directed energy deposition

Through the innovative design of interlayer connection materials, a high-performance wear-resistant and corrosion-resistant composite protective coating was successfully prepared on the surface of 5083 aluminum alloy using ultra-high-speed (0.5 m/s) laser energy deposition technology. By conducting orthogonal experiments and analyzing the coating morphology and non-destructive testing results, the optimal process parameters for preparing the Cu-Ni25 alloy interlayer and nickel-based alloy surface protection layer were determined. The bond strength and friction resistance of the composite coating and the substrate were tested by shearing and scratch tests. Furthermore, the wear and corrosion resistance of the nickel-based alloy protective layer and substrate were comparatively assessed using an abrasive wear tester, electrochemical workstation, and salt spray test chamber. The results show that the Cu-Ni25 alloy interlayer plays a good bridge role and realizes metallurgical bonding with the aluminum alloy matrix. Additionally, the addition of the nickel-based alloy surface protection layer yields a significant improvement in deformation resistance, wear resistance, and seawater corrosion resistance compared to the aluminum alloy substrate.

Numerical simulation method of aluminum alloy heat treatment process based on BP neural network

Abstract To address the shortcomings of the traditional BP neural network, this paper uses MEA to optimize the weights and thresholds in the traditional BP neural network, generates sufficient training samples to enhance the generalization ability of the model, and introduces a maturity judgment function to determine whether convergence is achieved. Based on the MEA-BP neural network, the effect of multiple aging on the microstructure of the aluminum alloy is investigated by numerical simulation method with the help of aging treatment to determine the heat treatment process of aluminum alloy. The results show that after the aging time exceeds 24 h, the hardness of the alloy tends to increase significantly, and the precipitation rate of the precipitated phase decreases. The peak hardness of the alloy at 75-120°C is the highest in the hardness curve at the fourth aging temperature of 90°C, which is maximum at the 7thh (119.4 HV). For the effect of the microstructure of the aluminum alloy, the T-phase was not found in the sweep diagrams of the specimens from the three aging states. This study can provide a theoretical basis and technical support for the formulation and optimization of the production process of aluminum alloy materials.

The Effects of Titanium Dioxide (TiO2) Content on the Dry Sliding Behaviour of AA2024 Aluminium Composite

The low density, low expansion coefficient, and strong corrosion resistance at room temperature of Aluminium alloys have made them a popular choice for engineering applications. In this study, Aluminium AA2024 alloys are prepared with different weight contents of ceramic material, titanium oxide (TiO2) nanoparticles (0%, 2.5%, 5%, and 7.5% wt.) of a particle size of 30 nm using the metal stir casting method. The hardness property and wear resistance with the effect of heat treatment are investigated using a pin-on-disc wear device for both the base alloy and the reinforced alloys. The result shows the prosperity of 5wt.% of TiO2 to attain the optimum hardness and wear resistance. Using the optimum content of TiO2 and heat treatment, the hardness and wear resistance of 5wt.% TiO2-AA2024 nanocomposite has been significantly improved after heat treatment over the unreinforced Aluminium matrix. Statistically, the hardness and wear resistance are improved by 68% and 22%, respectively. This is due to an increased number of fine precipitates besides their uniformly distributed after heat treatment. Furthermore, casting AA2024 Aluminium alloy material mainly has S (Al2CuMg) and Al3TiCu phases. The appearance of a large number of S phases causes a significant improvement in the properties of the alloy.

Nanosecond laser processing and surface quality of SiC particle-reinforced AA2024 composite, homogeneous AA2024 aluminum alloy, and SiC: A comparative experimental study

This study performed comparative experiments on ablation behavior and surface quality obtained by nanosecond laser processing of silicon carbide (SiC) particle-reinforced 2024 aluminum alloy matrix composite (SiCp/AA2024), homogeneous SiC, and 2024 aluminum alloy. A nanosecond laser with a pulse fluence range of 0.68 ∼ 6.83 J/cm2 was used at irradiate samples of these materials, which were then ablated by various numbers of scanning passes (1 to 10) at a fluence of 6.83 J/cm2. The material melting could be achieved only for homogeneous AA2024. The ablation depth for SiC exceeded that of the composite, and the former could be ablated with a pulse fluence exceeding 3.42 J/cm2. The composite ablation threshold was higher than 4.10 J/cm2. Due to the thermal transition between the reinforcement and matrix, the melting threshold of the composite’s AA2024 matrix was lower than that of homogeneous AA2024 alloy. Moreover, the ablation threshold of SiC particles exceeded that of homogeneous SiC. The ablated surface roughness for the homogeneous material showed a sudden increase because of melting or oxidization, while that of the composite exhibited a gradual increase. For homogeneous SiC, oxidization accompanied by ablation and the accumulation of oxidization products on the surface deteriorated the laser pulse processing quality, especially in multipass scanning. In contrast, the dispersed distribution of SiC particles in the composite improved the composite’s machining feasibility.

Surface modification effect of aluminium block on the tribological performance for super olein

PurposeThe purpose of this study is to investigate the use of micro-pits technology to the problem of tribological performance in a sliding motion.Design/methodology/approachVegetable oil is a sustainable and economically viable alternative to both mineral and synthetic oils, offering significant savings in both the cost of research and manufacturing. To solve the depriving issue and boost lubrication film thickness, the micro-pits on the surface may function as reservoirs that provide the oil to the contact inlet area. In this research, an aluminium block is used as the workpiece material in an evaluation of a through pin-on-disc tribotester. Lubricating oil in the form of super olein (SO) was used in the experiment.FindingsThe results show that the friction performance during a rubbing process between a hemispherical pin and an aluminium block lubricated with SO using aluminium alloy materials, AA5083, was significantly improved.Originality/valueIn this study, a material that breaks down called SO, which is derived from the fractionation of palm olein, was used to use a modified aluminium micro-pit sample that will serve as a lubricant reservoir in pin-on-disc tribotester.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0200/

Numerical analysis of whirl for drill string with aluminium alloy drill pipes in deep vertical well

In this study, a new finite element (FE) model using beam-shell composite elements is established. The model combines the advantage of computational speed for beam elements with the contact details of shell elements. The thermal instability of aluminium alloy materials and geothermal gradient are considered. Besides, kinematic contact model, Coulomb friction model, and initial imperfection are considered in this model. The drill string with aluminium alloy drill pipes of Songke-2 (SK-2) well is selected to simulation. The calculation results are consistent with the failure mode of the aluminium alloy drill pipes at engineering site. The effects of aluminium alloy drill pipes position, geothermal gradient, and rotational speed on the whirl characteristics of drill string with aluminium alloy drill pipes are analyzed. The results show that the closer the aluminium alloy drill pipes are to the drill bit, the more obvious the whirl phenomenon of the drill strings is. For deep wells with a maximum temperature of 170 °C, the temperature gradient has limited effect on the whirl state. The rotational speed has a significant impact on the whirl. When the rotational speed reaches 80 rpm, backward whirl occurs at the bottom of the borehole. Moreover, when the distance from the drill bit is different, the drill string will exhibit different whirl states. This work provides a new approach for modeling the dynamics of drill strings, selecting different element types based on the importance of different parts. Geothermal gradient is also considered in this model, which can help to calculate drill string dynamics for ultra deep drilling and geothermal drilling.

Microstructure and mechanical properties of induction rolling welded joint for A283GRC steel and 5052 aluminum alloy

In order to realize the welding of Fe/Al composite structure of automobile body, an induction rolling welding (IRW) was proposed. In this method, the eddy current and rolling force were generated by an induction heater and a rolling device respectvely, which were applied on the steel surface together. The Fe/Al welded joint under the combined action of eddy current heat and rolling force can be formed. The input power, feed velocity and rolling force were considered in this process. The results showed that IRW can realize the welding of A283GRC steel and 5052 aluminum alloy successfully. A continuous, uniform macroscopic morphology of welded joint and an optimal shear strength with 75 MPa can be obtained with the power 35 kW, the feed velocity 1 mm/s, and the rolling force 800 N. The intermetallic compound (IMC) in the welded joint consists of a lingulate Fe2Al5 towards the steel matrix and a saw-tooth FeAl3 towards the aluminum alloy matrix. The Fe2Al5 phase has the smallest Gibbs free energy and is the first to be generated at the interface. The weld joint width and IMC thickness in the IRW process increase with increasing power and decreasing feed velocity due to a larger heat input and longer heating time while increases with increasing rolling force due to a higher heat conducting efficiency. The shear strength can be increased significantly with increasing rolling force, due to a more contact area on the interface and a finer grain near the interface, which can prevent cracking effectively.

Certification of welder for tungsten inert gas welding in unmanned aerial vehicle systems

Aluminum and its alloys is one of the extensively used non-ferrous metal in aerospace engineering applications due to its excellent properties like higher strength to weight ratio, non-magnetic property, high thermal conductivity, good machinability, recyclability, and excellent formability. However, welding of aluminum and its alloys has always been a challenge due to drastic reduction in strength near heat affected zone (HAZ). Due to softness, ductility, lower melting point of aluminum and its alloys impose additional challenges to weld aluminum alloy components. Due to this, the quality and quantum of skill set needed to weld aluminum alloy joints for flight critical components is much more than that of welding of ferrous materials. The qualification and certification of welder is one of the prime requirements in welding applications especially in aerospace industry. This paper mainly discusses the various aspects involved in qualifying and certifying a welder for tungsten inert gas (TIG) welding process of aluminum alloys, which is treated as one of the special processes. The welder certification is a written verification that weld joints produced by welder meets the prescribed standard of welder performance. It is to verify the ability of an individual to execute a qualified welding procedure specification to produce a sound weld. Aluminum alloy 6xxx series is considered for base metal for sample preparation and weld joint assessment studies, as it is one of the prevalently used aluminum alloy material in unmanned aerial vehicle (UAV) applications. Weld samples are prepared as per internationally practiced standards and welding procedure specification (WPS) is recorded. Various mechanical tests carried out on weld samples during certification process are discussed in the paper. Weld joints are subjected to tensile testing, bending test and macro test. The certifying agencies are involved at every stage to ensure consistency of welder performance.

Studies and scientific research analysis of aluminium (Al7075) metal matrix composite surface morphology

A nano-composite is composed of one or more chemically distinct inert phases, and its structural and distinctive qualities are superior to those of the constituent parts acting separately. This review paper focuses on enhancing the mechanical properties of composites through the integration of micro- and nanoparticles into an aluminum matrix. The article provides an overview of Aluminum Alloy (7075) matrix composites. Due to their exceptional strength, metallic matrix composites made from aluminum alloys find frequent applications in aerospace, automotive, defense, marine, and industrial fields. Due to their ease of processing and heat-treatability, heat-treatable alloys such as AA2024, AA6061, and AA7075 have garnered the interest of numerous researchers. This is primarily because these alloys can be readily modified to exhibit properties that are suitable for specific applications. The article discusses the mechanical properties of Aluminum Metal Matrix Composites (MMCs) reinforced with one or more particulates, such as aluminum oxide (Al2O3), zirconium oxide (ZrO2), titanium oxide (TiO2), silicon carbide (SiC), graphite, and titanium diboride (TiB2), among others. AA7075 exhibits remarkable ultimate tensile strength, good corrosion and wear resistance, and enhanced thermal stability.

Optimizing microstructure and enhancing mechanical properties of Al–Si–Mg–Mn–based alloy by novel C-doped TiB2 particles

Grain size, grain orientation, the size and distribution of the precipitated phases are very important for the mechanical properties of particle reinforced aluminum matrix alloys. In this work, the effects of C-doped (C–TiB2) particles on the microstructure and properties of the Al–Si–Mg–Mn alloys were systematically studied. The results show that the as-cast grain size of (C–TiB2)/Al–Si–Mg–Mn alloy is refined to 29.7 μm by 0.5 wt% C–TiB2 particles, and the grain size instability due to static recrystallization can be effectively inhibited in the heat treatment progress after hot deformation, stabilizing the fine grain structure. Furthermore, 0.5 wt% C–TiB2 particles tend to distribute with the AlFeMnSi and Mg2Si phases, refining the size of precipitates. The C–TiB2 particles can also improve the geometrically necessary dislocation density and change the grain orientation of the T6 treated (C–TiB2)/Al–Si–Mg–Mn alloy, thus reducing the average value of the Schmidt factor and increasing the deformation difficulty. The above effects of 0.5 wt% C–TiB2 on the microstructure of the (C–TiB2)/Al–Si–Mg–Mn alloy cause the yield strength and the uniform elongation to synergistically improve by 13.8% and 18.7%, respectively, compared to the matrix alloy.

Construction of Al-Mg-Si-Cu(p) composite coating on aluminum alloy 1050 substrate

The AA6061 aluminum alloy matrix composite reinforced by copper particles was applied to the AA1050 aluminum substrate using a friction surfacing process. The effect of reinforcement content and pre-coating heat treatment condition of the consumable rod on the microstructure and mechanical properties was investigated. The results showed that coating with T6 treated consumable rod and increasing the mass fraction of copper powder resulted in higher temperature during friction surfacing. With increasing the mass fraction of copper powder, the average grain size of the coatings created with T6 and solid solutionized rods decreased. The average grain size of the coating in the samples created with the solid solutionized rod was 16% finer than that in the samples created with T6 rods. By increasing the mass fraction of copper to 20%, the wear resistance in coatings created with T6 and solid solutionized rods is increased by 28% and 24%, respectively, compared to that of the AA1050 substrate. Furthermore, by using a T6 rod and 20 wt.% copper, the shear strength, hardness, and wear resistance of the coating were 4%, 8%, and 5%, respectively, higher than those of the coating created with the solution-treated rod.

Study on the Influence of Surface Treatment Process on the Corrosion Resistance of Aluminum Alloy Profile Coating.

This work focuses on different surface treatment processes of the 6061 aluminum alloy profile coatings in the construction industry, mainly including the sand powder film coating, the flat powder coating, the hard anodized film, and the ordinary heat-sealing oxidized coating. The corrosion resistance of the coated aluminum alloy in a 3.5 wt.% NaCl solution (pH 6.5-7.5) and the influence of different surface treatment processes on the corrosion resistance of different samples were studied by scanning electron microscope (SEM) and electrochemical workstation. The result shows that with the increase in corrosion time, the corrosion inhibition performance of the four coated aluminum alloy materials decreased significantly, and the order of decline is: sand powder film coating > hard anodized film > flat powder coating > ordinary heat-sealing oxidized coating. When corroded in a 3.5 wt.% NaCl solution for 2 h, the corrosion inhibition performances of the flat powder coating and ordinary heat-sealing oxidized coating are poor, while the inhibition performances of the sand powder film coating and hard anodized film are good, and the inhibition performance follows the following sequence: the sand powder film coating > hard anodized film> the flat powder coating > ordinary heat-sealing oxidized coating. When corroded in a 3.5 wt.% NaCl solution for 200 h, the corrosion inhibition performances of the sand powder film coating and the flat powder coating are poor, while the inhibition performances of hard anodized film and ordinary heat-sealing oxidized coating are good, and the inhibition performance follows the following sequence: hard anodized film > ordinary heat-sealing oxidized coating > the sand powder film coating > the flat powder coating.

Effect of tool pin profile on the heat generation model of the friction stir welding of aluminium alloy

Abstract The present work aims to model the three-dimensional heat transfer coupled with the material flow model of 7075-T6 aluminium alloy material using the three tool pin profiles, square, pentagon, and hexagon, in the friction stir welding process. The temperature rise and fluid flow behaviour from the top to the bottom of the tool were evaluated. Also, the strain rate and dynamic viscosity variation were found near the tool pin and shoulder region. The results showed that the frictional contact heat between the shoulder surface and workpiece was responsible for the maximum heat generation. The probe area was minimum in the square tool pin geometry, which results in high heat generation due to the maximum shoulder surface contact area with the workpiece model. Furthermore, the analytical formula for calculating the heat generation on the tool shoulder/workpiece interface and the tool pin/workpiece contact region were also evaluated. The numerical modelling of heat generation was evaluated by COMSOL Multiphysics V5.3a software.

High-precision turning and ultra-smooth direct polishing of aluminum alloy mirrors.

Due to the high surface roughness requirements of aluminum alloy mirrors used in the visible light band, there are still great challenges in single point diamond turning of high-surface quality aluminum alloy mirrors. In this paper, a processing method for aluminum alloy mirrors is proposed. Based on single point diamond turning technology, the prediction model of aluminum alloy surface roughness was established. The mapping relationship between the surface roughness of the aluminum alloy mirror and each turning parameter was obtained, and the maximum possible surface quality was achieved. On the basis of the turning results, the method of small tool polishing was used to remove the turning texture generated by the copy effect of the tool arc radius, suppress errors of the medium and high-frequency, and reduce the surface roughness. The single abrasive removal efficiency model was established and mechanical removal in the polishing process was analyzed. Combined with the chemical action in the polishing process, two types of polishing liquid-acidic and neutral, were prepared and analyzed. The optimal polishing parameters were obtained through multiple single-factor experiments. On the basis of this, the surface roughness of the aluminum alloy after turning was optimized. The results show that the value was reduced from 4.811 to 1.482 nm, an increase of 69.2%. This method can effectively improve the machining accuracy of aluminum alloy mirrors and provide an important process guarantee for the application of aluminum alloy materials in visible-light systems.

Performance enhancement of photovoltaic modules with passive cooling multidirectional tapered fin heat sinks (MTFHS)

The electrical output of photovoltaic (PV) modules degrades with continued exposure to extreme temperatures caused by solar radiation. The uniqueness of this research lies in the utilization of multidirectional fins with varying heights, which effectively accelerate heat transfer in PV cooling systems by inducing a transition in the boundary layer within the confined zone of the fins. The research aims to investigate the effect of using Multidirectional Tapered Fin Heat Sinks (MTFHS) to improve the efficiency of PV modules by utilizing aluminum alloy material as heatsinks. The proposed multidirectional design aims to facilitate enhanced heat transfer by promoting airflow in the central area of the PV module. The experimental procedures in our study differ from previous research as we utilized the latest generation of PV modules (405 Wp, PERC Half-cut cells) to fill the discrepancy between laboratory-based investigations and practical applications. Two PV modules were tested for an outdoor parametric analysis under outdoor operating conditions, with solar irradiance recorded from 200 to 1000 W/m2 and ambient temperatures ranging from 26° to 38 °C. Findings indicated that the proposed MTFHS could lower PV module temperatures by 12 ⁰C. Reduced temperature boosts PV module efficiency by 1.53%. Cooling advancements proved vital in contributing to sustainability in PV system installations.

Fabrication of graphite-reinforced 6201Al matrix composite with simultaneous enhancement of mechanical and electrical properties by multi-pass friction stir processing

In this study, graphite-reinforced 6201 aluminum alloy matrix composites were fabricated by multi-pass friction stir processing. The mechanical properties and electrical conductivity of the composites were tested, the microstructure and composition of the composites were analyzed by scanning electron microscope and Raman spectroscopy. The results showed that the graphite-reinforced 6201Al matrix composite achieved simultaneous improvement of mechanical and electrical properties compared to the base material, with a 19.5 % increase in ultimate tensile strength and a 1.2 % increase in electrical conductivity. Microstructural and compositional analysis revealed that the graphite reinforcement in the composites was significantly fragmented during FSP, and its size decreased while the number of atomic layers reduced with increase in FSP passes. A directly bonded Al-C interface is observed between the graphite reinforcement and the matrix, and no interface products such as Al4C3 were generated. The graphite reinforcement in the matrix simultaneously serves as a hindrance to dislocation motion and the expansion of microvoids during the tensile process, thereby leading to an enhancement in the tensile strength of the composite. The improvement in the electrical conductivity of the composite is attributed to two factors. On one hand, the structure and properties of graphite-reinforced phase is transformed to be closer to graphene after the severe plastic deformation during FSP process. On the other hand, the directly bonded Al-C interface between the matrix and the reinforcement is able to transfer electrons across the interface.

Experiment and mechanism investigation on the effect of heat treatment on residual stress and mechanical properties of SiCp/Al–Cu–Mg composites

Low-volume fraction particle-reinforced aluminum matrix composites (PRAMCs) are commonly prepared using powder metallurgy (PM) technology, followed by heat treatment processes to improve the performance of PRAMCs. PRAMCs are prone to produce significant uneven residual stresses during the quenching process. It is difficult to eliminate the quenching residual stress of PRAMCs via the heat treatment process of the matrix aluminum alloy. Therefore, this study systematically investigates the effects of solid solution and artificial aging treatment processes on residual stress, mechanical properties, and microstructure of SiCp/Al–Cu–Mg composites through orthogonal and single-factor experimental methods. After optimizing the heat treatment process, minor residual stress with a 71.6% von Mises residual stress relief rate and good comprehensive mechanical properties are achieved. Based on the experimental results, macro and micro mechanisms of residual stress evolution and strengthening of SiCp/Al–Cu–Mg composites during heat treatment are revealed, providing valuable insights into the process of heat treatment of PRAMCs.

The effect of laser shock peening on very high cycle fatigue properties of laser welded 2A60 aluminum alloy joints

Laser shock peening (LSP) technology has the advantages of deep residual compressive stress field, low degree of cold hardening and controllable hardening area. The surface modification of welded structures has broad prospects. To predict the very high cycle fatigue (VHCF) life of an aero engine impeller, it is of great engineering significance to study the VHCF performance of 2A60 aluminum alloy. The effects of LSP on VHCF properties of laser welded joints were investigated from the S-N curve, fracture morphology, residual stress, hardness, and roughness. The results show that the S-N curves of the 2A60 aluminum alloy matrix under the condition of ethanol cooling belong to the infinite life type. The S-N curves of welded and LSP samples belong to the continuous decline type. In the process of LSP, the fatigue crack source is transferred from the surface of the sample to the second surface of the sample, which not only counteracts the residual tensile stress introduced on the surface of the sample during welding but also introduces considerable residual compressive stress on the surface of the sample. The roughness is reduced, thus improving the fatigue stsample's fatigue strength and life. The strengthening mechanism of LSP is discussed from two aspects of dislocation strengthening and residual stress. The LSP results in many dislocation proliferation within the grain, and the dislocation entanglement and dislocation wall are formed among the dislocations. The original coarse crystal is divided into multiple subgrains to achieve the effect of grain refinement. Grain refinement and high-density dislocation increase the hardness of the material.

Temperature Resistance Properties of Unidirectional Laminated Cf/SiC-Al Prepared by PIP and Vacuum Pressure Infiltration.

Material used for aero-engine fan blade requires excellent mechanical properties at high temperature (300 °C). Continuous carbon-fiber-reinforced silicon carbide ceramic matrix composites (Cf/SiC) are necessary candidates in this field, possessing low density, high strength, high modulus, and excellent high-temperature resistance. However, during the preparation process of Cf/SiC, there were inevitably residual pores and defects inside, resulting in insufficient compressive strength and reliability. The vacuum pressure melting infiltration process was used to infiltrate low melting point and high wettability aluminum alloys into the porous Cf/SiC composite material prepared by the precursor impregnation cracking process, repairing the residual pore defects inside the body. The porosity of porous Cf/SiC decreased from 49.65% to 5.1% after aluminum alloy repair and strengthening. The mechanical properties of Cf/SiC-Al composite materials strengthened by aluminum alloy repair after heat treatment were studied. The tensile strength of the as-prepared Cf/SiC-Al was 166 ± 10 MPa, which were degraded by 13~22% after heat treatment. The nonlinear sections of stress-displacement curve of as-treated samples were shorter than that of as-prepared sample. The hardness of aluminum alloy matrix after 300 °C 1 h heat treatment was 58 Hv, which was not obviously reduced compared with the sample without heat treatment. The vacuum infiltration of aluminum alloy is expected to have guiding significance for repairing and strengthening internal defects in ceramic matrix composites.