High Performance Aluminum Alloys Research Articles

Impact of lattice designs and production parameters on mechanical properties of AlSi10Mg in laser powder bed fusion

Abstract This study investigates the impact of lattice designs and production parameters on the mechanical properties of AlSi10Mg fabricated using Laser Powder Bed Fusion (L-PBF). The research explores the production and performance of gyroid, diamond, and lidinoid lattice structures under varying scanning speeds (600, 900, 1,200 mm s−1). Key findings indicate that scanning speed significantly influences mechanical properties and energy absorption capabilities. The gyroid lattice structure produced at 600 mm s−1 exhibited the highest compressive strength (76.51 MPa) and energy absorption (28.57 MJ m−3). SEM-EDS analysis revealed no substantial structural defects, while porosity and microstructural deformations were observed at higher scanning speeds. Finite element simulations demonstrated localized buckling and fissure formation in lattice structures under compressive loads. The study highlights the critical role of production parameters in optimizing the mechanical performance of L-PBF-manufactured AlSi10Mg, offering insights into achieving cost and time efficiencies in additive manufacturing processes. This comprehensive analysis contributes to advancing the application of L-PBF in producing complex, high-performance aluminum alloy components for industrial use.

First-Principles Calculations on Relative Energetic Stability, Mechanical, and Thermal Properties of B2-AlRE (RE = Sc, Y, La-Lu) Phases

The relative energetic stability, mechanical properties, and thermodynamic behavior of B2-AlRE (RE = Sc, Y, La-Lu) second phases in Al alloys have been investigated through the integration of first-principles calculations with the quasi-harmonic approximation (QHA) model. The results demonstrate a linear increase in the calculated equilibrium lattice constant a0 with the ascending atomic number of RE, while the enthalpy of formation ΔHf exhibits more fluctuating variations. The lattice mismatch δ between B2-AlRE and Al matrix is closely correlated with the transferred electron et occurring between Al and RE atoms. Furthermore, the mechanical properties of the B2-AlRE phases are determined. It is observed that the calculated elastic constants Cij, bulk modulus BH, shear modulus GH, and Young’s modulus EH initially decrease with increasing atomic number from Sc to Ce and then increase up to Lu. The calculated Cauchy pressure C12-C44, Pugh’s ratio B/G, and Poisson’s ratio ν for all AlRE particles exhibit a pronounced directional covalent characteristic as well as uniform deformation and ductility. With the rise in temperature, the calculated vibrational entropy (Svib) and heat capacity (CV) of AlRE compounds exhibit a consistent increasing trend, while the Gibbs free energy (F) shows a linear decrease across all temperature ranges. The expansion coefficient (αT) sharply increases within the temperature range of 0~300 K, followed by a slight change, except for Al, AlHo, AlCe, and AlLu, which show a linear increase after 300 K. As the atomic number increases, both Svib and CV increase from Sc to La before stabilizing; however, F initially decreases from Sc to Y before increasing up to La with subsequent stability. All thermodynamic parameters demonstrate similar trends at lower and higher temperatures. This study provides valuable insights for evaluating high-performance aluminum alloys.

Nanotechnology-enabled rapid investment casting of high-performance wrought aluminum alloys

High-performance wrought aluminium alloys are widely used in automobiles and aerospace industries owing to their high-volume precipitates after heat treatment. Investment casting as one of the precision manufacturing methods provides great potential to achieve excellent surface finishes and complex geometry for aluminium alloy components. However, these high-performance aluminium alloys are almost impossible to be investment cast due to their hot cracking susceptibility and severe shrinkage during solidification. In this study, we introduce nanotechnology to improve the processability of high-performance wrought aluminium alloys in investment casting by adding a small volume fraction of nanoparticles into the aluminium alloys. This work showed the unprecedented success of nanotechnology-enabled investment casting of high-strength wrought aluminium alloys (AA6061, AA2024, and AA7075) for excellent mechanical properties.

Insight into microstructure evolution of in-situ ZrB2np/AA6111 composites with both excellent room and high temperature properties

With rapid development of aerospace and automobile, the service condition of structural components becomes increasingly harsh, diverse and high mechanical properties are urgently needed. In this work, an advanced in-situ ZrB2np/AA6111 composite with excellent room and high-temperature properties was prepared via Al-Zr-B reaction system. The microstructure revealed that ZrB2 nanoparticles with regular polygonal shapes ranged from 10 to 150 nm approximately, and a good α-Al/ZrB2 interface bonding was confirmed. The agglomeration of ZrB2 particles was significantly weakened during hot extrusion. Due to the inhibiting effect on dislocation motion and pinning effect on grain boundaries induced by ZrB2 particles, fine recrystallized grains were obtained in ZrB2/AA6111 composites after extrusion. Compared with AA6111 matrix alloy, the yield strength, ultimate tensile strength and elongation of AA6111-3ZrB2 composites at room temperature and 300 °C were increased by 18.9 %, 12.7 %, 50.0 % and 34.1 %, 22.4 %, 42.4 %, respectively. An excellent room and high-temperature strengthening effect was simultaneously achieved assisted by ZrB2 particles. The improvement of room-temperature properties was mainly owed to the Grain refinement and Orowan bypassing strengthening mechanisms. The good high-temperature properties mainly relied on the superior coarsening resistance of ZrB2 particles which could fully played the Orowan strengthening effect and well protected the grain boundaries at high temperature. This work provides a feasible approach to design high-performance aluminum alloys and is beneficial for the further development of modern industries.

Research progress, application and development of high performance 6000 series aluminum alloys for new energy vehicles

For the development of new energy automobile industry and the trend of automobile lightweight have put forward a huge demand for high-strength lightweight materials, so developing high strength aluminum alloys is particularly momentous. As the most widely used aluminum alloy, 6000 series aluminum alloys (Al–Mg–Si alloys) have the advantages such as better mechanical properties, outstanding welding properties, excellent formability and fine processing capability, and therefore have obtained great attention as the structural materials. In addition, the Al–Mg–Si alloys with low density and corrosion resistance not only reduce the total weight of the car, but also extend the service life when subjected to chemical corrosion, which effectively achieve energy saving and emission reduction. This paper summarizes the research progress of 6000 series aluminum alloys, in particular, and reviews the methods of microalloying and particle strengthening, and their effects on the microstructure and properties of the alloy, thus providing a reference for the subsequent development of high-performance aluminum alloys in automobile and aerospace industries.

Designing unique and high-performance Al alloys via machine learning: Mitigating data bias through active learning

Data-driven modelling, such as machine learning (ML), has great potential to streamline the complexity involved in designing new alloys. However, such powerful predictive models require a high-quality dataset, which is limited in the alloy field due to selection and reporting biases. These biases lead to out-of-distribution (OOD) regions where ML models suffer from predictive performance degradation, limiting the design of innovative alloys. To overcome this problem, we propose a ML-based design strategy for unique and high-performance aluminium (Al) alloys, incorporating multi-objective genetic algorithm (MOGA) and active learning. To guide active learning, the cosine similarity metric embedded MOGA pinpoints unique and high-strength Al alloys in OOD regions for experiments. Our study demonstrates the deficiency of initial ML models when trained on the biased dataset and subsequent improvement in retrained models after applying active learning with alloys suggested by MOGA. On this basis, a new Al alloy that is distinct from the existing dataset is developed with a yield tensile strength of 688 MPa, ultimate tensile strength of 738 MPa, and elongation of 7.5 %. This finding highlights the importance of the inclusion of OOD results and the efficiency of ML in alloy design.

Application and performance analysis of advanced materials in engine lightweight

This paper discusses the application and performance analysis of advanced materials in engine lightening. Firstly, we analyze the properties of high performance aluminum alloy, titanium alloy and composite materials, including their composition, mechanical properties and high temperature resistance. Then, the practical application effects of these materials in key components such as automobile and aero-engine are analyzed through concrete cases. For example, the introduction of micronutrient and improvements in heat treatment processes have significantly increased the strength and corrosion resistance of high-performance aluminium alloys. Titanium alloy is widely used in the key parts of aero-engine because of its high strength and light weight, which greatly improves the performance of engine. The low density and high strength of the composite make it an ideal choice for reducing engine weight. Finally, we discuss the current challenges and future directions, and explore solutions to reduce costs, improve processing efficiency and develop new alloys, in order to provide guidance and reference for the further development of engine lightweight technology.

Methods of neutralization of iron-containing phases in cast aluminum alloys of the Al-Si-Cu system with iron content of up to 1,5 mass. %

The article discusses the effectiveness of various modifiers, namely chromium (Cr), molybdenum (Mo), vanadium (V), and cobalt (Co), in neutralizing the negative impact of iron on the properties of aluminum alloys in the Al-Si-Cu system by altering the morphology of iron-containing phases. The current advancements in the modification of aluminum alloys are examined, focusing on the influence of these elements on microstructural changes and mechanical properties. An in-depth analysis of the microstructure was conducted, and the optimal concentrations of the modifying elements were identified to achieve enhanced mechanical characteristics. The study highlights that the addition of Cr, Mo, V, or Co facilitates the formation of a fine-grained structure and significantly reduces the size of iron-containing phases to approximately 10 μm. Furthermore, the research elaborates on the thermodynamic interactions between iron and the modifying elements, providing insights into the mechanisms by which these modifiers influence the crystallization process and phase distribution within the alloy. This study opens new avenues for the development of high-performance aluminum alloys with optimized microstructures through precise control of modifier concentrations. The improved alloys exhibit superior mechanical properties, making them suitable for applications in various industrial sectors, including automotive and other industries, where high strength and reliability are critical. Experimental results demonstrate that the strategic addition of Cr, Mo, V, and Co can effectively mitigate the adverse effects of iron inclusions, leading to alloys with enhanced ductility, tensile strength, and overall performance. The findings suggest that these modifiers not only refine the grain structure but also promote a more uniform distribution of phases, thus improving the alloy's resistance to cracking and other forms of mechanical failure. The insights gained from this research provide a valuable foundation for further exploration and optimization of aluminum alloys for high-demand applications, emphasizing the critical role of microstructural engineering in achieving desired material properties

Effect of Mg/Si ratio on synergistic improvement of formability and yield strength in Al-Mg-Si-Zn alloys

The design of Al-Mg-Si-Zn series alloys combines the advantages of 6xxx and 7xxx series alloys and breaks through the limitations of strength and formability matching of traditional alloys. In this study, we achieved an exceptional strength-formability combination in the Al-0.84Mg-0.79Si-3.38Zn (wt.%) alloy. Following a solution treatment at 550 °C for 3 min, the alloy exhibited an elongation of ∼36.8%, with a yield strength of ∼356 MPa after artificial aging at 175 °C for 8 h. The effects of different Mg/Si ratios (∼0.6, ∼1.2, and ∼2.5, at.%) on the strength-formability interplay in Al-Mg-Si-Zn alloys were investigated. The alloy with a low Mg/Si ratio (∼0.6) facilitated the precipitation of fine β'' phases characterized by a high number density (∼8.4 nm−3 × 10−5). A Mg/Si ratio of ∼1.2 proved advantageous for precipitating larger β'' phases with a higher volume fraction (∼0.69%), resulting in an elevated precipitation strengthening effect (∼290 MPa). However, with an increase in the Mg/Si ratio to ∼2.5, the reduced availability of Si atoms for forming Mg-Si clusters led to a decrease in the number density of precipitates. Additionally, the interaction among Fe, Mn, and Si elements resulted in the presence of blocky α-Al(FeMn)Si phases, as opposed to the needle-like β-AlFeSi phases, in the alloy with a Mg/Si ratio of ∼1.2. This effectively prevented the degradation of elongation. Our findings present a comprehensive strategy for the compositional design of high-performance aluminum alloys.

Revealing the exceptional cryogenic strength-ductility synergy of a solid solution 6063 alloy by in-situ EBSD experiments

A solid solution 6063 aluminium alloy features an exceptional combination of strength and ductility at 77 K. Here, the deformation mechanisms responsible for superior strength-ductility synergy and excellent strain hardening capacity at a cryogenic temperature of the alloy were comparatively investigated by in-situ electron backscatter diffraction (EBSD) observations coupled with transmission electron microscopy (TEM) characterization and fracture morphologies at both 298 and 77 K. It is found that kernel average misorientation (KAM) mappings and quantified KAM in degree suggest a higher proportion of geometrically necessary dislocations (GNDs) at 77 K. The existence of orientation scatter partitions at 77 K implies the activation of multiple slip systems, which is consistent with the results of potential slip systems calculated by Taylor axes. Furthermore, dislocation tangles characterized by brief and curved dislocation cells and abundant small dimples have been observed at 77 K. This temperature-mediated activation of dislocations facilitates the increased dislocations, thus enhancing the strain hardening capacity and ductility of the alloy. This research enriches cryogenic deformation theory and provides valuable insights into the design of high-performance aluminium alloys that are suitable for cryogenic applications.

Effects of hot extrusion texture on anisotropy in microstructure and mechanical properties of spray formed Al–Zn–Mg–Cu 7055 aluminum alloy

The Al–Zn–Mg–Cu 7055 aluminum alloy was meticulously fabricated through spray forming (SF) technology, followed by hot extrusion and T76 treatment. This comprehensive process allowed for a thorough investigation of its microstructural characteristics, mechanical properties, and fatigue behavior. Post-treatment analysis revealed that the SF-7055 aluminum alloy exhibited no notable segregation or porosity defects, ensuring its exceptional quality and reliability. The microstructural analysis revealed a uniform distribution of refined grains and dispersed precipitates, contributing to the material's strength. Mechanical testing demonstrated that the hot extruded SF-7055 aluminum alloy exhibits superior tensile strength and elongation, with significant anisotropy in mechanical properties favoring the extrusion direction (ED) over the transverse direction (TD). Fatigue testing under varying cyclic stresses revealed an extended fatigue life in the ED-oriented specimens, attributed to the texture-induced resistance to crack initiation and propagation. The study underscores the effectiveness of SF and hot extrusion in enhancing the SF-7055 aluminum alloy's performance, making it a viable candidate for critical aerospace applications. The findings provide valuable insights into the relationship between processing, microstructure, and properties, offering a pathway to the design and fabrication of high-performance aluminum alloys.

Engineering application study of high-performance aluminum alloy 6A13-T6

To address the application challenges of the novel high-strength aluminum alloy material 6A13-T6 in engineering, experimental and numerical simulation studies were conducted. Firstly, material tensile tests, axial compression tests, and pure bending tests were conducted, and the applicability of the specification was evaluated. Subsequently, finite element models were employed to analyze the overall mechanical performance and economic indicators of three typical engineering structures (grid shells, grid trusses, and glass curtain walls) based on the test results. The findings indicate that 6A13-T6 exhibits a non-proportional yield strength (f0.2) of 340 MPa, an ultimate strength of 352 MPa, and a post-necking elongation of 14.5%. Design calculations for axially compressed and flexural members made of 6A13-T6 high-strength aluminum alloy can be conservatively carried out following Chinese design specification. The use of 6A13-T6 aluminum alloy can reduce material consumption in structures, with a maximum reduction of up to 29% compared to other commonly used aluminum alloys and up to 72% compared to common steel materials. Therefore, the new high-strength aluminum alloy 6A13-T6 has obvious engineering application value and has been used in a hotel curtain wall project.

Multi-Mode Damage and Fracture Mechanisms of Thin-Walled Tubular Parts with Cross Inner Ribs Manufactured via Flow Forming.

In order to study the multi-mode damage and fracture mechanisms of thin-walled tubular parts with cross inner ribs (longitudinal and transverse inner ribs, LTIRs), the Gurson-Tvergaard-Needleman (GTN) model was modified with a newly proposed stress state function. Thus, tension damage and shear damage were unified by the new stress state function, which was asymmetric with respect to stress triaxiality. Tension damage dominated the modification, which coupled with the shear damage variable, ensured the optimal prediction of fractures of thin-walled tubular parts with LTIRs by the modified GTN model. This included fractures occurring at the non-rib zone (NRZ), the longitudinal rib (LIR) and the interface between the transverse rib (TIR) and the NRZ. Among them, the stripping of material from the outer surface of the tubular part was mainly caused by the shearing of built-up material in front of the rollers under a large wall thickness reduction (ΔT). Shear and tension deformation were the causes of fractures occurring at the NRZ, while axial tension under a large TIR interval (l) mainly resulted in fractures on LIRs. Fractures at the interface between the TIR and NRZ were due to the shearing applied by rib grooves and radial tension during the formation of ribs. This study can provide guidance for the manufacturing of high-performance aluminum alloy thin-walled tubular components with complex inner ribs.

New insight into the role of Cu addition on surface nanocrystallization and corrosion behavior of aluminum alloy

Realization of surface-reinforced aluminum alloys with excellent corrosion resistance remains a major topic. Herein, a novel method based on combination of electron beam evaporation plating and surface alloying was proposed. Results revealed that the current density is one order of magnitude less than that of the substrate and that the impedance value is doubled. The nanometer-scale refinement of the grains and the homogenous dispersion of nanocrystallization Al2Cu in the modified layer of aluminum alloy contributed to the enhancement of corrosion resistance. This study is expected to provide a new sight for the development of Cu-reinforced high-performance aluminum alloys.

Quantitative study of the effect of high-performance zinc alloy coating technology on the life of mechanical components

Abstract Corrosion of mechanical components has been of wide interest in recent decades. Corrosion is caused by physicochemical action between a metal and its environment, which can result in changes in the metal’s properties and functional damage in mechanical components. The main corrosion manifestations of zinc alloy coatings in marine environments are discussed in this paper, which first explores the application of high-performance aluminum alloy coatings in industry. Subsequently, the ZAS35 alloy used for this paper was experimentally prepared, and orthogonal tests were utilized to determine the optimum matching values of process parameters for zinc alloy coatings to generate materials. The hardness and wear resistance of ZAS35 were evaluated against other zinc alloys. An iterative learning control algorithm was employed to determine the thickness of the zinc alloy coating. The optimal control of the steady-state process of coating thickness can be achieved by using the NARX dynamic neural network model as a predictive identification model for zinc alloy coating thickness. Finally, data were collected using an optical microscope to quantitatively analyze the effect of zinc alloy plating on mechanical life. When the thickness of zinc alloy is 1.7 μm, the probability of life is [947.56,978.36]×103h interval t=0.999, which is improved by 409~684.11×103h compared with the plating thickness of 1.10μm . After adding aluminum elements to zinc plating, the corrosion potential of the plating decreases from −800mV to −1000mV, and the zinc-aluminum alloy prevents electrochemical corrosion of the plated layer with cathodic corrosion inhibition.

Recent advances and future trend of aluminum alloy melt purification: A review

Aluminum, the most produced non-ferrous metal in the world, is highly regarded for its light weight, high specific strength, and excellent thermal conductivity. With the continuous development of aerospace, precision electronics, photovoltaic semiconductors and other emerging strategic industries, the demand for high-performance aluminum alloys is also booming. The paper discusses recent advances in aluminum alloy melt purification, focusing on the development of conventional purification treatment and novel purification treatment of aluminum alloy melt. The advantages and disadvantages of adsorption purification, non-adsorption purification and integrated purification are also summarized. Additionally, the article points out the shortcomings of the current research on aluminum alloy melt purification and gives an outlook on the future research direction.

Defects control of aluminum alloys and their composites fabricated via laser powder bed fusion: A review

Laser powder bed fusion (L-PBF) technique, as the mainstream technology in metal additive manufacturing, enables the fabrication of aluminum alloys and their composite components with high precision and design freedom, thereby advancing structural lightweighting in various application domains, such as aerospace and transportation. Nevertheless, aluminum powders present challenges including high laser reflectivity, high thermal conductivity, low melting point, and susceptibility to oxidation. Consequently, defects such as pores, solidification cracks, orientation anisotropy, and surface roughness commonly exist in L-PBFed aluminum alloy and composite parts. These defects severely compromise the mechanical performance and dimensional accuracy of L-PBFed parts. Thus, extensive research efforts have been focused on defect control in the L-PBFed aluminum alloys and their composites. However, a systematic summary and in-depth analysis of the formation mechanism and controlling strategy of various defects is still absent, which is the key to develop high performance aluminum alloys and their composites via L-PBF. In this review, a thorough analysis and summary of the causes of defects are provided, followed by an in-depth analysis and conclusion of defect control strategies and mechanism in L-PBF. Furthermore, we also present an outlook on the challenges and research opportunities in L-PBFed aluminum alloys and their composites in the last section, which we hope could inspire more new development of high-performance aluminum alloys and their composites via L-PBF.

Direct aging of additively manufactured A20X aluminum alloy

This study investigates the effect of direct aging on a newly developed high-performance aluminum alloy A20X for laser powder bed fusion. Three different temperatures (180 °C, 200 °C, and 220 °C) and nine different heat treatment durations (5 min to 30 h) were considered. The material exhibited significant softening (up to 23.7 % hardness drop) after direct aging. The extent of softening was proportional to the temperature and duration of heat treatment. During direct aging, incoherent Al2Cu (θ) precipitates ({110}θ ǁ {220}Al) coarsened and the volume fraction remained constant (4.52–4.63 %). The average precipitate size grew by up to ∼100 % through direct aging and no metastable precipitates (such as θ′ or Ω) formed, suggesting the absence of supersaturated matrix in as-printed A20X. Accordingly, the yield and tensile strengths of the alloy dropped by up to 27 % and 19.4 %, respectively. The continuous Mg/Ag solute wall observed at grain boundaries in the as-printed state caused serrated plastic flow due to the locking/unlocking of dislocations. Longer aging treatments generated discrete solute co-clusters along the grain boundaries and TiB2/Al interface promoting smoother plastic flow.

Development of a solid-state extrusion-roll-bonding based additive manufacturing (ERB-AM) technology for aluminum alloys

To solve the poor printability issue of high-performance aluminum alloys in additive manufacturing processes, a solid-state hybrid additive manufacturing (AM) technology, combining extrusion and roll bonding operations, is proposed, in which the extruded aluminum layers are soundly bonded through the hot-rolling operation. In this feasibility and early-stage research, a lab-scale extrusion-roll-bonding prototype machine is designed and built. Aluminum alloy, AA1060, owing to its relatively low loading requirements for the prototype, is used for the proof of the concept. The extrusion-roll-bonding tests have been undertaken at different temperatures and rolling reductions to identify optimal processing parameters. The corresponding bonding quality was estimated using an optical microscope (OM). Also, miniature AM tensile samples were tested to evaluate the tensile properties of the bonding interfaces. It is of great interest to see that the AM material did not fracture at the bonding interface and its stress-strain response is similar to that of the original material. In-depth analyses on the interfacial grain and oxide distribution and their effects on the interfacial strength were undertaken using a transmission electron microscope (TEM) and scanning electron microscope (SEM)/electron backscatter diffraction (EBSD). This study demonstrates the proposed solid-state AM technique can successfully manufacture aluminum alloys at their solid states, achieving comparable mechanical properties to their wrought states. This new solid state AM technique may enable a wide range of alloys with poor printability to be used in various industries to produce safety-critical and large, structural components with simple geometry.

Characterisation of Microstructure and Special Grain Boundaries in LPBF AlSi10Mg Alloy Subjected to the KoBo Extrusion Process

Grain boundary engineering (GBE) enhances the properties of metals by incorporating specific grain boundaries, such as twin boundaries (TB). However, applying conventional GBE to parts produced through additive manufacturing (AM) poses challenges, since it necessitates thermomechanical processing, which is not desirable for near-net-shape parts. This study explores an alternative GBE approach for post-processing bulk additively manufactured aluminium samples (KoBo extrusion), which allows thermo-mechanical treatment in a single operation. The present work was conducted to examine the microstructure evolution and grain boundary character in an additively manufactured AlSi10Mg alloy. Microstructural evolution and grain boundary character were investigated using Electron Back Scattered Diffraction (EBSD) and Transmission Electron Microscopy (TEM). The results show that along with grain refinement, the fraction of Coincidence Site Lattice boundaries was also increased in KoBo post-processed samples. The low-Σ twin boundaries were found to be the most common Coincidence Site Lattice boundaries. On the basis of EBSD analysis, it has been proven that the formation of CSL boundaries is directly related to a dynamic recrystallisation process. The findings show prospects for the possibility of engineering the special grain boundary networks in AM Al–Si alloys, via the KoBo extrusion method. Our results provide the groundwork for devising GBE strategies to produce novel high-performance aluminium alloys.