Al–Si–Mg alloys are increasingly employed in HPDC automotive structural components due to their lightweight potential and recyclability. In this context, the use of recycled AlSi10MnMg alloys represents a promising strategy to reduce the environmental footprint of aluminum components. However, the fatigue performance of these alloys, particularly when subjected to different heat treatments, remains insufficiently understood. This study investigates the fatigue behavior and fracture mechanisms of a 75 pct recycled AlSi10MnMg alloy, using specimens directly extracted from an industrial HPDC automotive component. Specimens retaining the original as-cast surface were subjected to three different heat treatment conditions: E-coating simulation (EC), artificial aging (AA), and annealing (AN). Microstructural characterization, nanoindentation mapping, and high-cycle fatigue tests were combined with fractographic analysis to correlate microstructural features with fatigue crack nucleation and propagation mechanisms. Results revealed a heterogeneous cross-sectional microstructure, with a discontinuous eutectic-rich skin layer over a coarser dendritic core, generating a hardness gradient that significantly influenced fatigue behavior. Among the investigated conditions, AA provided the highest fatigue strength (138 ± 4 MPa), while EC and AN showed lower performance. Fractographic observations revealed that fatigue crack nucleation was associated with the local discontinuity of the skin layer, whereas crack propagation and overall fatigue resistance were primarily governed by the hardness distribution induced by heat treatment. Finally, the environmental impact assessment focused on the effect of the AA and EC heat treatments further indicated that AA, despite its additional processing energy, reduces the overall life-cycle environmental burden by extending component lifetime.

Recycled aluminum-silicon alloys offer environmental advantages by reducing raw materials consumption and carbon emissions. However, heat treatment response and corresponding mechanical behavior remain insufficiently characterized, limiting their applicability. This study investigates two secondary AlSi7Mg0.3 alloys, containing 76 % and 97 % recycled aluminum, focusing on the influence of increased iron content on aging and mechanical properties. A primary alloy was used as a benchmark. Specimens were produced by gravity diecasting and subjected to T6 heat treatment, involving solutionizing at 535 degrees C for 4.5 h, water quenching, and artificial aging at temperatures from 160 degrees C to 190 degrees C for durations up to 184 h. Aging curves revealed that secondary alloys responded similarly to primary alloy, achieving higher hardness values. Four aging conditions were selected for tensile characterization. Aging condition of 160 degrees C for 4.5 h was identified as optimal, yielding a strength-ductility balance in peak-aged specimens (YS up to 268 MPa, UTS up to 310 MPa, and elongation no less than 4.3 %). Minor differences were observed between primary and secondary alloys, with a clear trade-off: increased Fe content improved strength but reduced ductility. Mechanical behavior was interpreted through microstructural characterization, defect analysis, and fractographic examination, all of which confirming the suitability of recycled alloys for high-performance applications.

This study investigates the performance and environmental impact of a 100% recycled EN 45500 aluminum alloy subjected to T6 heat treatment, using its primary counterpart as a benchmark. Both alloys were produced by gravity die casting under controlled laboratory conditions and subsequently characterized from a microstructural and mechanical standpoint. The recycled alloy exhibited a higher iron content, promoting the formation of Fe-based intermetallic compounds, which increased defect density and reduced ductility compared to the primary alloy. Heat treatment parameters were optimized to balance mechanical performance with energy efficiency. Tensile testing revealed that the recycled alloy achieved mechanical properties comparable to those of the peak-aged primary alloy when aged at 160 degrees C for 4.5 h, a less energy-intensive condition than the 180 degrees C for 4.5 h required by the primary alloy. The environmental impact analysis demonstrated a significant reduction in carbon footprint, from 19.6 kgCO2eq/kgAl for the primary alloy to 2.47 kgCO2eq/kgAl for the recycled one. For 100% recycled EN 45500 alloy, the heat treatment, including solution treatment and aging, accounted for 92.3% of CO2eq emissions, underscoring the relevance of heat treatment optimization. Overaging tests demonstrated that the recycled EN 45500 retained copper-driven thermal stability. Overall, the findings highlight the capability of recycled aluminum to meet both mechanical performance and sustainability requirements to produce advanced automotive applications.

The increasing use of recycled aluminium in automotive applications requires the development of energy-efficient heat treatments capable of optimizing mechanical performance while preserving microstructural integrity. In this study, the effect of annealing on the microstructure and mechanical behaviour of a recycled AlSi7MnMg alloy produced by high-pressure die casting was systematically investigated. Annealing treatments were carried out in the temperature range 340–400 °C for holding times between 0.5 and 2 h. The results showed a progressive reduction in hardness, yield strength, and ultimate tensile strength with increasing annealing temperatures and times, accompanied by a significant increase in ductility. The overall mechanical performance was further assessed through a toughness-based quality index, enabling a comprehensive comparison between the different annealing conditions. The microstructural evolution was dominated by spheroidization and coarsening of eutectic silicon, while Fe-based intermetallic compounds exhibited only a mild coarsening. Fractographic observations confirmed a transition towards a ductile mechanism at elevated annealing temperatures. The optimal compromise between strength and ductility was achieved at 340 °C × 2 h (YS = 101 MPa, UTS = 199 MPa, ef = 8.0

Complex structures in AlSi10Mg alloy produced by Powder Bed Fusion-Laser Beam (PBF-LB) show high specific strength and an advantageous surface-to-volume ratio. However, in the as-built condition they are characterized by a high roughness that may worsen their performance. To overcome this limitation, a multilayer coating was applied, comprising: (i) an electroless Ni-9

This work investigates the effect of a high-pressure Solution Treating and Aging (STA) heat treatment on the room-temperature (RT) and high-temperature (550 degrees C) tensile properties of the near-alpha Ti6242 alloy produced by PBF-LB. The treatment combines solutioning with Hot Isostatic Pressing (HIP) at 1000 bar, followed by argon quenching and aging. High-pressure heat-treatment parameters were first optimized by studying two alpha+beta solution temperatures (960 and 990 degrees C), corresponding to primary-alpha fractions of 25 % and 50 %. All samples were aged at 600 degrees C for 4 or 8 h to promote a bilamellar microstructure. The condition solutioned at 960 degrees C and aged for 8 h (HIP960_8) was selected for mechanical testing. In the second phase, HIP960_8 was compared with a standard STA treatment without HIP, using water quenching and identical thermal parameters (STA960_8), to evaluate the effect of cooling rate. Both were also compared with a beta-solution STA treatment with pressurized nitrogen cooling (HT1040_8) designed to produce a fully lamellar structure. Atom Probe Tomography revealed Ti3Al precipitation in STA960_8, leading to higher YS and UTS than HIP960_8 at RT (+8 % on YS, +11 % on UTS) and 550 degrees C (+7 % on YS, +8 % on UTS). In contrast, HIP960_8 provided an excellent strength-ductility balance, with elongation increased by 40 % at RT and 22 % at 550 degrees C due to its reduced defect content. No STA condition formed silicides because of the low Si content, which contributed instead through solid-solution strengthening, particularly in HT1040_8. Tests at 550 degrees C confirmed that the bilamellar structure of HIP960_8 offers benefits comparable to solid-solution strengthening in HT1040_8.

Recycled aluminum–silicon alloys provide significant environmental benefits by reducing the consumption of raw materials and lowering carbon emissions. However, their industrial application is limited by the presence of iron-based intermetallic compounds and the insufficient investigation in the literature regarding their effects on mechanical behavior. This study focuses on a recycled EN 42000 alloy, comprising 95% recycled aluminum, with a focus on the effect of its elevated iron content (0.447 wt%) on aging behavior and mechanical performance. Laboratory-scale specimens were produced through gravity die casting and subjected to T6 heat treatment, consisting of solution, quenching, and artificial aging from 160 °C to 190 °C for up to 8 h. To investigate overaging, analyses were conducted at 160 °C and 170 °C for durations up to 184 h. Tensile tests were conducted on specimens aged under the most promising conditions. Based on innovative quality indices and predictive modeling, aging at 160 °C for 4.5 h was identified as the optimal condition, providing a well-balanced combination of strength and ductility (YS = 258 MPa, UTS = 313 MPa, and e% = 3.9%). Mechanical behavior was also assessed through microstructural and fractographic analyses, highlighting the capability of EN 42000 to achieve properties suitable for high-performance automotive components.

The design of complex-shaped aluminum castings, such as cylinder heads, is commonly based on mechanical data obtained from separately cast specimens. This approach may lead to inaccurate stress and fatigue life predictions by overlooking the effects of local solidification conditions and resulting heterogeneous microstructures formed in industrial casting conditions. This study investigates microstructural and mechanical properties of a sand-cast AlSi7Cu1.3Mg0.6 alloy, comparing separately cast specimens with those extracted from critical regions of a hot isostatic pressed cylinder head. Tensile and hardness measurements were related to local microstructural and fractographic features. Regions subjected to high cooling rates (e.g., the combustion chamber) showed fine secondary dendrite arm spacing (SDAS) and a uniformly fibrous eutectic Si morphology, comparable to that of separately cast specimens. In contrast, areas with lower cooling rates (e.g., the bolt columns) exhibited SDAS values up to 2.8 times larger, coarse plate-like eutectic Si particles, and elongated intermetallic phases up to an order of magnitude larger. These microstructural differences resulted in a reduction in tensile strength by 31

Titanium alloys produced via powder bed fusion-laser beam exhibit a wide range of applications for high-performance components, due to their excellent strength-to-weight ratio. However, their poor wear resistance remains a significant limitation. Heat treatment offers a viable approach for enhancing the tribological performance of these alloys by modifying their microstructure. This study examines the influence of annealing temperature on the tribological behavior of the alpha-beta titanium alloy Ti-6Al-2Sn-4Zr-6Mo during sliding against a quenched and tempered AISI 52 100 in a block-on-ring configuration. The predominant wear mechanism identified in all samples is oxidative, while severe adhesion zones are observed in the as-built alloy. Annealing below the beta-transus temperature (HT875) yields the largest enhancement in wear resistance, reducing the wear volume by 59%. This superior performance is attributed to the high ductility imparted by the microstructural coarsening, which allowed for the generation of a compact and functional mechanically mixed layer (MML), and to the high tendency for strain hardening, induced by tribological interactions, which guarantees enhanced load-bearing capacity. Conversely, despite being 14% harder than the HT875 condition, the HT600 condition demonstrates a 56% higher wear volume, which is attributed to the instability of the MML formed during sliding.

Secondary aluminum alloys are produced with end-of-life scraps and are gaining importance for environmental sustainability, thanks to their low intrinsic carbon footprint and energy saving compared to the primary ones. They are increasingly used in the automotive sector for large and complex cast components. However, recycled alloys contaminants like Fe promote the formation of brittle intermetallic compounds, which negatively affect tensile strength and ductility. This study compares the mechanical performance and environmental impact of primary and recycled high pressure die casting AlSi10MnMg (EN AB 43500) alloy under as-produced and heattreated conditions. Samples were extracted from a die-cast automotive component and subjected to annealing and an optimized T6 heat treatment to balance strength and ductility. Microstructural analysis using field emission scanning electron microscopy revealed a similar pores area fraction, as well as shape, size, and distribution of brittle acicular beta-Al5FeSi and polygonal alpha-Al15(Fe,Mn)3Si2 Fe-rich phases in the primary and recycled alloys under different heat treatment conditions. This similarity justifies the comparable mechanical behavior of the primary and recycled alloy, characterized by limited ductility in the as-produced condition, often insufficient for safety-critical structural components. Heat treatments significantly improved ductility, increasing it by 40-50 % after annealing and nearly doubling it after T6 due to the fragmentation, spheroidization, and coarsening of the eutectic Si. However, the microstructure change reduces strength by a third after annealing and by 20 % after T6, ultimately influencing the final fracture mechanisms. Moreover, heat treatments increase energy consumption, with annealing and T6 leading to about 25 % and 30 % rises, respectively, making them justified only for elongation enhancement.

Bound metal deposition (BMD) is a valid 3D printing solution from an economic perspective. Still, the resulting mechanical properties are intrinsically lower than selective laser melting and electron beam melting ones and, in some cases, are also lower than metal injection molding (MIM). The optimization of the printing parameters is fundamental to level off this issue and to ensure mechanical performance competitive with MIM ones. In light of this, the present work focuses, for the first time, on the optimization of the printing parameters for a Ti6Al4V alloy. The effect of three fundamental parameters, that is, layer thickness, nozzle temperature, and printing speed, is investigated, and the 3D printing process is optimized by exploiting the design of experiment and the surface response analysis techniques. The results are extremely auspicious, considering that the optimum configurations display a tensile strength of 915 MPa, which is perfectly comparable with MIM components. The statistical analysis demonstrates that nozzle temperature, printing speed, and their interaction are the most relevant parameters and the 3D printing optimum is achieved with a nozzle temperature of 160 °C and a printing speed of 15 mm s −1 .

The study investigates the influence of microstructures on fatigue behavior and failure mechanisms of the α-β titanium alloy Ti6246, fabricated via Powder Bed Fusion-Laser Beam (PBF-LB). In particular, the investigation assesses the effect of two post-processing heat treatments, namely α-β annealing at 875 °C (AN875) and solution treatment at 825 °C followed by aging at 500 °C (STA825), on the alloy’s rotating and bending fatigue behavior. The results indicate that the STA825 condition provides superior fatigue resistance (+25%) compared to AN875, due to the presence of a finer bilamellar microstructure, characterized by thinner primary α lamellae (αp) and a more homogeneous distribution of secondary α lamellae (αs) within the β matrix. Additionally, an investigation conducted using the Kitagawa–Takahashi (KT) approach and the El-Haddad model, based on the relationship between the fatigue limit and defect sensitivity, revealed improved crack propagation resistance from pre-existing defects (ΔKth) for the STA825 condition compared to AN875. Notably, the presence of fine αs after aging for STA825 is effective in delaying crack nucleation and propagation at early stages, while refined αp contributes to hindering macrocrack growth. The fatigue behavior of the STA825-treated Ti6246 alloy was even superior to that of the PBF-LB-processed Ti64, representing a viable alternative for the production of high-performance components in the automotive and aerospace sectors.

To enhance the sustainability of aluminum castings, the use of recycled alloys is increasing due to their lower energy demand and reduced carbon footprint. At the same time, semisolid metal (SSM) rheocasting is emerging as a viable alternative to High Pressure Die Casting (HPDC), enabling the processing of low-silicon aluminum alloys. This reduces the need for critical raw materials, such as primary silicon, and allows casting at lower temperatures, further improving efficiency. However, contaminants typically present in recycled alloys, particularly iron, influence castability, defect formation, and mechanical performance, requiring further investigation. This study analyzes the tensile properties and cracking mechanisms of semi-solid cast AlSi7Mg alloys with varying iron content: primary (Fe = 0.08%), recycled (Fe = 0.19%), and recycled high iron (Fe = 0.42%), produced via the Rheometal™ method. Tensile testing was performed on as-cast and T6 samples. Statistical analysis was applied to evaluate variability and statistical significance of the results. The results show that recycled alloys have a higher defect density at an increased iron content, leading to lower elongation, reduced strength, and greater variability than in the primary alloy (recycled alloy Fe=0.19%: as-cast Rp 0.2 =113±8 MPa, R m =208±15 MPa, e f =4.13±0.95 %; T6 Rp 0.2 =240±17 MPa, R m =279±27 MPa, e f =1.40±0.20 %). The T6 treatment improved strength but reduced ductility due to defect enlargement and surface blistering caused by solubilization step, particularly pronounced in the recycled alloy with high-iron content. Scanning electron microscopy (SEM) fractography indicated that oxide films act as nucleation sites for β-Al 5 FeSi intermetallics, which promote shrinkage defects and thereby limit elongation.

The growing need to reduce the carbon footprint of transportation is driving vehicle lightweighting using thin-walled aluminum high-pressure die casting (HPDC) components. Using recycled rather than primary aluminum i. e., from bauxite, further enhances sustainability by reducing energy consumption and emissions. Accordingly, also heat treatments (HTs) with limited energy demand and low risk of dimensional distortions and blistering, like annealing and direct artificial aging, are today preferred. Many HPDC vehicle components also undergo finishing treatments at similar temperatures, such as e-coating, or are exposed to elevate service temperatures that can affect their final properties. Therefore, assessing their strength and thermal management capabilities is critical. The present study investigates the effects of HTs on the high-temperature tensile strength and electrical/ thermal conductivity of an automotive component produced from an AlSi10MnMg HPDC alloy with a high recycled content. The mechanical and functional properties are correlated with microstructural features, including the size, morphology, and interparticle spacing of eutectic silicon, as modified by HTs. In turn, fracture surfaces analysis reveals the relationship between microstructural changes and failure mechanisms. Results clearly show that silicon particles play a crucial role in determining the investigated properties, significantly influencing strength and conductivity. Moreover, despite being produced through recycling processes, the recycled alloy exhibits overall performance comparable to that of primary alloys. This confirms its potential for sustainable lightweight solutions without compromising properties.

High-cycle fatigue behaviour of W360 steel produced by Powder Bed Fusion - Laser Beam (PBF-LB) is explored by comparing post-processing of industrial interest, involving both heat treatments (conventional quenching and multiple tempering (CHT), or innovative high-pressure heat treatment (HPHT)) and surface finishing (sandblasting, machining, shot peening). The combination of HPHT and machining returns the highest fatigue strength (767 f 10 MPa) by reason of: i) reduced number and size of process-related defects compared to CHT and machining (457 f 19 MPa); ii) reduced surface roughness compared to HPHT and sandblasting (243 f 23 MPa) and HPHT and shot-peening (403 f 19 MPa). The latter combination, however, shows an improved fatigue strength than the sandblasted one, thanks to compressive residual stress in the superficial region. The correlation between killer defect and fatigue performance is also discussed based on the Kitagawa-Takahashi diagram and the El-Haddad model, and compared to the conventionally manufactured steel.

In recent years, the increasing need to use recycled aluminum alloys has driven the exploration of advanced processes. Among these, thixocasting is attractive due to its potential to produce high-performance components. Alloy composition and manufacturing routes influence semisolid Al-Si-Mg alloys' microstructure and mechanical properties. In order to exploit the potentiality of aluminum alloys that comes from metal scraps recycling, it is helpful to evaluate the influence of iron on the microstructure of recycled alloys by measuring the Rheocast Quality Index (RQI). The study focused on the production and testing of thixo-cast samples in two recycled AlSi7Mg aluminum alloys, with high (approximate to 0.40 wt.% Fe) and low (approximate to 0.15 wt.% Fe) iron content both featuring a high recycling rate (exceeding 70 % of the total alloy), and in a primary (i.e., from ore) AlSi7Mg alloy (approximate to 0.10 wt. % Fe) serving as a benchmark. The microstructural characterization, carried out by optical and scanning electron microscope equipped with both electron backscatter diffraction and energy dispersive X-ray spectroscopy, focused on grain size, alpha-Al globules size and shape, and intermetallic amount. The high Fe content recycled alloy exhibited a higher area fraction of iron intermetallic compounds, coarser grains, and larger and not well spheroidized alpha-Al globules than the primary one with an RQI of about 0.30. Instead, the low-iron recycled and the primary alloy showed similar microstructures with a comparable RQI of about 0.40-0.45.

Ti-6Al-4Zr-2Sn-6Mo alloy is one of the most recent titanium alloys processed using powder bed fusion-laser beam (PBF-LB) technology. This alloy has the potential to replace Ti-6Al-4V in automotive and aerospace applications, given its superior mechanical properties, which are approximately 10

This paper examines the relationship between the magnetization behavior and crystal lattice orientations of Fe-Si alloys intended for magnetic applications. A novel approach is introduced to assess anisotropy of the magnetic losses and first magnetization curves. This method links the magnetocrystalline anisotropy energy of single crystal structures to the textures of polycrystalline materials through a vectorial space description of the crystal unit cell, incorporating vectors for external applied field and saturation magnetization. This study provides a preliminary understanding of how texture influences magnetic loss rates and the first magnetization curves. Experimental results from Electron Back-Scattered Diffraction (EBSD) and Single-Sheet Tests (SSTs), combined with energy considerations and mathematical modeling, reveal the following key findings: (i) a higher density of cubic texture components, whether aligned or rotated relative to the rolling direction, decreases magnetic anisotropy, suggesting that optimizing cubic texture can enhance material performance; (ii) at high magnetic fields, there is no straightforward correlation between energy losses and polarization; and (iii) magnetization rates significantly impact magnetization loss rates, highlighting the importance of considering these rates in optimizing Fe-Si sheet manufacturing processes. These findings offer valuable insights for improving the manufacturing and performance of Fe-Si sheets, emphasizing the need for further exploration of texture effects on magnetic behavior.

The AlSi10Mg alloy is one of the most studied alloys processed by the Powder Bed Fusion-Laser Beam (PBF-LB). Many already published works focus on post-process heat treatments to reduce residual stress or improve mechanical strength. Instead, the present study aims to identify direct artificial aging (AA) heat treatment able to optimize both aspects, thus enhancing the trade-off between strengthening and residual stress relief for the PBF-LB AlSi10Mg alloy produced using a no-heated platform. Higher temperatures (190–240 °C) than those typically used in AA heat treatment were selected based on thermal analysis to benefit both residual stress relief and precipitation of reinforcing phases from the supersaturated solid solution of the metastable as-built alloy. The effects of AA heat treatment on mechanical properties (i.e. hardness) and residual stress were evaluated by plotting aging curves and by XRD and Raman analyses and demonstrated that different trade-offs between strengthening and stress relief can be achieved by tuning heat treatment parameters (temperature and time). In particular, the exposure at the lowest temperature (190 °C) induced a partial decrease in residual stress and a slight increase in hardness. By increasing heat treatment temperature and soaking time, the relief was more significant, whilst the decrease in hardness was rather limited. The results are supported by the microstructural changes observed on the samples due to the different heat treatment conditions applied and show the feasibility of designing an AA heat treatment for the PBF-LB AlSi10Mg alloy capable of satisfying the mechanical response required by the final application.