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This work investigates silver (Ag) microalloying as an efficient route to enhance the mechanical response of AlSi10Mg consolidated by vacuum hot pressing. Pre-alloyed AlSi10Mg powders were modified with 0–8 wt% Ag and densified in a single step without post-heat treatment. Comprehensive characterization, including Vickers hardness testing, dry sliding wear evaluation, and three-point bending experiments, revealed a clear optimum at 6 wt% Ag. The alloy exhibited a peak hardness of 74 HV (approximately 63% higher than the base alloy), a ∼42% reduction in wear rate (from 14.2 × 10−3 to 8.3 × 10−3 mm3 m−1), and a flexural strength of 476 MPa with a deflection of 3.8 mm values comparable to those reported for SLM-built AlSi10Mg and nearly fourfold higher than the unmodified hot-pressed alloy. These improvements are attributed to Ag-induced grain refinement, the formation of hard intermetallic phases (confirmed by SEM/EDS), and enhanced densification facilitated by Ag during sintering. Beyond 6 wt%, Ag agglomeration caused a decline in properties, underscoring the need for compositional optimization. Unlike previous studies focused on casting or additive manufacturing, this powder metallurgy-based strategy provides a cost-effective alternative by eliminating complex processing steps while delivering competitive mechanical performance. This study establishes clear composition-process-property linkages and highlights strong potential for deploying these alloys in lightweight structural components.

The effect of multipass friction stir processing (FSP) on the microstructure and mechanical properties of an AlSi10Mg alloy produced by laser-powder bed fusion was investigated. FSP was performed at a rotational speed of 950 rpm and traverse speed of 85 mm/min. The results indicated that FSP destroyed the coarse grain structure in the as-built AlSi10Mg by generating fine and equiaxed grain structures with shear texture components of A1*(111)[1¯1¯2] and A2*(111)[112¯], in addition to causing fragmentation and refinement of the Si networks. FSP reduced the tensile strength slightly but significantly improved ductility. One-pass FSP exhibited superior mechanical properties compared with the two- and three-pass scenarios. The higher strength of the one-pass sample was attributed to the strengthening mechanisms induced by the Si particles, which were grown by repeated FSP. The higher ductility of the one-pass sample was explained using the kernel and grain average misorientations. Furthermore, the post-FSP microstructural evolution and fracture behavior of the samples were discussed.

In view of the importance of accurately measuring the relative density of a selective laser melted (SLMed) part for optimizing the selective laser melting (SLM) processing parameters, suitable procedures of the Archimedes method considering the surface-connected cavities were proposed by comparing the results using the Archimedes method with image analysis. The effects of the SLM processing parameters on the relative density of AlSi10Mg were investigated using the proposed procedures of the Archimedes methods and image analysis. Fourteen SLMed samples were produced by different SLM processing parameters according to Doehlert Matrix. The regression models correlating relative density and three SLM processing parameters (laser power, scan speed, and hatching distance) were built and the optimum parameter combination to get a high relative density was obtained. By plotting the response surfaces and contours of the regression models, it was found that the relative densities are both higher at the combination of the higher scan speed, higher power, and lower hatching distance and at the combination of a lower scan speed, a moderate laser power, and a optional hatching distance. It was also found that the parameter of hatching distance is the crucial parameter to get a high relative density and to get high mechanical property.

While the quality of parts produced by additive manufacturing is generally evaluated by surface roughness, relative density, and mechanical properties, the issue of dimensional accuracy is not examined sufficiently. However, dimensional accuracy is very important for the final use and finishing of a product. Since the dimensional change mainly occurs due to shrinkage resulting from the heat energy applied during the sintering process, the effect of production parameters in the additive manufacturing method is quite large. To minimize shrinkage and increase dimensional accuracy, manufacturing parameters need to be optimized and meticulously examined. This study was aimed at determining the effects of manufacturing parameters on geometric tolerances in the production of parts using the additive manufacturing method. AlSi10Mg powder alloy and selective laser melting (SLM) technology were used in the additive manufacturing of this alloy in part production. Twelve different laser powers and scanning speeds, as well as fixed scanning range and layer thickness parameters, were used in production. In determining geometric tolerances, features such as hole diameter change, deviation from angularity, deviation from perpendicularity, deviation from flatness, and deviation from parallelism were taken into consideration. As a result of the study, deviation values increased in high and low laser power/scanning speed combinations. Minimum deviation amounts were obtained in the range of 250–310 laser power and 785–974 scanning speed, which are the middle values of the parameters used. The optimum values of different output responses have been obtained with different production parameters, but for the final use and quality control approval of the product, it is necessary to determine the input parameters at which all output responses are optimal. In this process, the gray relational analysis optimization method, which is one of the multi-criteria decision-making methods, was preferred. As a result of the optimization, the optimum manufacturing parameters for geometric tolerances were determined as the 290/911 laser power/scanning speed combination.

The selective laser melting (SLM) technique is progressively changing the traditional manufacturing processes due to rapid molding and high forming accuracy. However, the density and microstructure induced by the process parameters have a significant influence on the material properties. In general, these process parameter windows are obtained experimentally based on the energy density requirements of the material. The combination of schemes is often huge in number, which is a time-consuming and laborious process. On the other hand, the fluctuations in molten pool temperature influence the printing quality of the part, resulting in differences in performance. The orthogonal experimental design method was used to determine the macroscopic properties of SLM-ed AlSi10Mg parts in this work. Combining the density and mechanical properties, the optimal process parameter window was deduced, and the influence of critical process parameters was investigated via range analysis. The optical microscope (OM) and scanning electron microscope (SEM) observations were used to correlate the microstructure to macroscopic properties. The influence mechanism of layer thickness and volumetric energy density (VED) variation on the molten pool morphology was investigated by the finite element method. The knowledge of optimized process parameters is essential for SLM-ed parts with better mechanical properties, which could more accurately guide the structural design.

The AlSi10Mg alloy was processed by selective laser melting using both hot- and cold-build platforms. The investigation was aimed at defining suitable platform pre-heating and post-process thermal treatment strategies, taking into consideration the peculiar microstructures generated. Microstructural analyses, differential scanning calorimetry, and high-resolution diffraction from synchrotron radiation, showed that in the cold platform as-built condition, the amount of supersaturated Si was higher than in hot platform samples. The best hardness and tensile performance were achieved upon direct aging from cold platform-printed alloys. The hot platform strategy led to a loss in the aging response, since the long processing times spent at high temperature induced a substantial overaging effect, already in the as-built samples. Finally, the standard T6 temper consisting of post-process solution annealing followed by artificial aging, resulted in higher ductility but lower mechanical strength.

Selective laser melting (SLM) technology is playing an increasingly important role in today’s manufacturing industry. However, the surface quality of SLM samples is relatively poor and cannot be directly applied to industrial production. Therefore, this paper focuses on the post-treatment process of SLM AlSi10Mg alloy. First, the rough machining is performed by a grinding process (GP), and then, the magnetic abrasive finishing (MAF) is used for finish machining. The experiment results show that the combination of GP and MAF can effectively reduce the surface roughness and improve the surface quality of SLM AlSi10Mg alloy. The GP reduced the surface roughness to drop from 7 μm (after SLM forming) to about 0.6 μm, and the rough surface with defects such as spheroids and pits evolved into the fine surface with scratches and pores. The MAF reduced the surface roughness to a minimum of 0.155 μm, which resulted in excellent surface morphology. The surface hardness after the GP was higher, and the MAF reduced the hardness of the GP surface.

A new strategy is proposed to modify the grain structure and crystallographic texture of laser-powder bed fusion AlSi10Mg alloy using multi-pass friction stir processing (FSP). Accordingly, 1–3 passes of FSP with 100% overlap were performed. Scanning electron microscopy and electron backscattered diffraction were used for microstructural characterization. Continuous dynamic recrystallization and geometric dynamic recrystallization are the governing mechanisms of grain refinement during FSP. The stir zones have bimodal grain structures containing large and fine grains. The multi-pass FSP caused a considerable increase in the volume fraction of the large-grained area in the stir zone, which contained higher values of low-angle boundaries and sharp shear texture components of B(11¯2)[110] and B¯(1¯12¯)[1¯1¯0]. The formation of low-energy grain boundaries in the stir zone and alignment of the low-energy crystallographic planes with the surface of the sample made the strategy of using multi-pass FSP a promising candidate for corrosion resistance enhancement in future studies. Moreover, the detailed evolution of the grains, texture components, grain boundaries, and Si particles is discussed.

The staircase effect, balling effect, and powder adhesion as well as other problems in additive manufacturing (AM) forming all lead to the poor uniformity and high roughness of the sample surfaces. Therefore, there exist differences in the physical and mechanical properties of the samples. In this paper, the spherical composite magnetic abrasive particles (MAPs) are used for magnetic abrasive finishing (MAF) experimental investigations and process optimization of the AM sample surface. According to the Box-Behnken design principle of the response surface methodology, the finishing effects of different process parameters (spindle speed, feed speed, and machining gap) of MAF on the samples prepared by selective laser melting (SLM) with different formed angles are studied, the quadratic regression equations are established, and the validity of the equations are assessed by ANOVA and 3D response surfaces. After that, MAPs with smaller size were selected for the fine MAF experiments with the optimized parameters. Finally, we found that the optimal parameters of MAF for the same material with different forming angles are similar, but the polishing time consumed is quite different. After the MAF experiments, the changes of the surface Vickers hardness, roughness (Ra), and microscopic morphology are analyzed. The surface roughness of each sample is reduced from the initial 4–10 μm to about 100 nm, and the diversities in hardness are also reduced. MAF significantly improves the defects of poor surface uniformity caused by inconsistent forming angles.

Residual stresses in metal alloys fabricated by the powder bed fusion-laser beam (PBF-LB) method exhibit anisotropy influenced by laser scanning and building orientations. This study maps nanoscale residual stresses within a single grain of PBF-LB AlSi10Mg alloy using various transmission electron microscopy (TEM) modalities. Residual stress maps were obtained for both as-built and T6 heat-treated samples along scanning and building orientations. Post-analysis revealed that T6 heat treatment reduced tensile stress compared to as-built samples. For example, in the [1̅00] crystallographic direction, average tensile and compressive residual stresses in the building direction decreased by ~ 70% after T6 treatment. Anisotropy in residual stresses was also observed; in the [1̅00] direction, average residual stresses in scanning orientation were ~ 13% and ~ 23% higher than the building direction in as-built and T6-treated samples, respectively. Heat treatment effects were further examined using image-based finite element method (FEM) simulations to understand the stress-driven mechanisms behind Si eutectic break-up and Si precipitate diffusion into the Al matrix. The results revealed regions of tensile and compressive stress within Si eutectic zones, identifying them as sources for Si diffusion and nucleation of Si-based precipitates within the matrix.