In this study, austenitic oxide dispersion-strengthened (ODS) steels were fabricated by mechanical alloying (MA) of 316L stainless steel with 1 wt% of either nano- or micro-sized Y2O3 particles, followed by pulse plasma sintering (PPS). The effects of MA duration (5, 10, and 50 h) and Y2O3 particle size on the microstructure, mechanical properties, and corrosion resistance were systematically investigated. The morphology and size of the alloyed powder particles were strongly influenced by MA parameters: longer milling times produced finer, though more irregularly shaped, particles. Increasing the milling duration led to a higher fraction of fine grains and elevated dislocation densities, indicating grain refinement driven by discontinuous recrystallization. Mechanical testing revealed that strength was primarily controlled by the MA duration. Samples milled for 50 h reached the highest strength regardless of Y2O3 particle size, owing to the combined effects of grain refinement and Orowan strengthening. This strength gain, however, was accompanied by a loss in ductility. Corrosion behavior, assessed via electrochemical methods and salt spray tests, was strongly dependent on internal strain and grain boundary characteristics. The best corrosion resistance was observed in samples milled for 5 h, which had lower dislocation densities and smaller grain boundary areas. In contrast, prolonged milling (50 h) increased grain boundary density and misorientations, accelerating corrosion-particularly in steels reinforced with microsized Y2O3 particles.

Formability of steel sheet metals depends primarily on mechanical properties of material that influence the material's ability to undergo plastic deformation without risk of fracturing. This article presents the use of multilayer artificial neural networks (ANNs) to evaluate the effect of uniaxial tensile test parameters on selected mechanical properties of 0.7-mm-thick DX56D+Z100-M-C-O steel sheets. Samples were cut from different areas of the coil and at different angles (0°, 45° and 90°) relative to the sheet rolling direction. Samples also came from different batches of materials. Yield strength, ultimate tensile strength and uniform elongation were determined under variable crosshead speeds between 2 and 600 mm/min. The quality parameters of the ANNs were the value of the coefficient of determination (the higher the better) and the prediction error (the smaller the better) determined for the test set. The predictive quality of ANNs was characterized by the coefficient of determination R2 = 0.7849-0.9864, depending on the ANN architecture, the output variable and type of neuron activation function used. As crosshead speed increased, elongation of samples decreased. However, as crosshead speed decreased, yield strength decreased. The influence of sample orientation on the analyzed mechanical parameters of the sheet was smaller than the effect of crosshead speed. This was also confirmed by sensitivity analysis of the input parameters.

CoCrWMo alloys produced by laser powder bed fusion (L-PBF) are promising materials for load bearing biomedical implants such as hip and knee joint replacements. Surface defects and microstructural anisotropy introduced during printing raise concerns about long term wear performance in physiological conditions. The influence of build orientation and laser surface remelting on the defect structure, surface oxide composition and wear behaviour of CoCrWMo alloy produced by laser powder bed fusion was investigated. Samples were fabricated at build orientations of 0°, 30°, 75° and 90°, and analysed both in the as printed condition and after Nd:YAG laser remelting. Build orientation strongly affected the defect structure, with the highest dislocation densities for the 30° and 75° samples (8.71 × 1013 m-2 and 8.08 × 1013 m-2) and the lowest for the 90° sample (0.94 × 1013 m-2). Laser remelting increased the crystallite size from 10.91-46.88 nm to 56.25-82.57 nm and increased the fraction of edge dislocations. It also changed the oxide composition from cobalt dominated to chromium dominated, with Cr2O3 rising from 12-15% to 49-54%. Hardness increased from 407 to 440 HV to 469-508 HV. Although friction increased slightly, laser-remelted samples exhibited wear-track morphologies consistent with the formation of more stable tribo-oxidative layers during sliding. This is related to the formation of a more stable oxide layer during sliding. The results show that build orientation and laser remelting control defect structure and oxide composition, which determine wear behaviour and can improve the performance of additively manufactured biomedical components.

This study investigates the effect of build orientation on the microstructure, mechanical response, dislocation behaviour, and wear mechanisms of CoCrWMo alloy produced by Selective Laser Melting. Samples were fabricated at seven build angles (0°–90°) and analysed using SEM, XRD, EBSD, nanoindentation, and ball-on-disc tribological testing. A strong correlation was obserwed between grain orientation and wear behaviour. Low-angle samples exhibited well-aligned columnar grains with high dislocation mobility and mild abrasive wear, whereas high-angle samples showed misaligned grains, reduced dislocation activity, and delamination-driven wear. Quantitative analysis revealed that microstrain decreased from approximately 0.0058 at 0° to 0.0031 at 90°, while crystallite size increased from 19 to 57.8 nm, indicating significant microstructural relaxation at higher build angles. EBSD analysis performed near plastically deformed regions revealed a strain-induced FCC→HCP phase transformation at higher build angles. The presence of the HCP phase leads to the formation of additional phase boundaries, which modify the local deformation behaviour. Dislocation mobility decreased by nearly an order of magnitude, from 4.48 × 10⁻⁹ m/s at 0° to 0.56 × 10⁻⁹ m/s at 90°, reflecting increasing constraints on plastic deformation. Despite similar wear volumes across orientations, SEM analysis of wear debris confirmed distinct mechanisms governed by microstructural anisotropy. Although hardness remained relatively constant (4.1–4.4 GPa), Young’s modulus decreased from 182 to 191 GPa to 176 GPa with increasing build angle, indicating pronounced elastic anisotropy. These findings highlight the critical role of grain boundary orientation and dislocation dynamics in controlling the tribological response of SLM-fabricated CoCrWMo alloy and provide new insight into proces-structure-property relationships in additively manufactured materials.

The manufacture of thin-walled structures via laser powder bed fusion (L-PBF) is associated with a number of technological challenges, such as control of the melting process, geometric stability, and surface quality. This paper describes the fabrication of inclined thin walls from M300 maraging steel using the L-PBF process. Thin walls were fabricated with thicknesses of 0.2–1.0 mm (in 0.2 mm increments) and inclination angles of 30–90° (in 15° increments). The geometric quality of the as-fabricated samples was analyzed using an optical 3D scanner, and the sample porosity was also examined using X-ray computed tomography and optical microscopy. Finally, the Vickers microhardness and surface roughness of L-PBF-processed inclined thin walls were examined. A geometric analysis revealed that the wall inclination angle relative to the building platform had a significant effect on the reproduction quality. The largest geometric deviations, with high porosity and high surface roughness, were observed for samples built at 30° and 45° angles. Vertical walls (with inclination angle 90°) gave the most precise reproduction of the CAD design and had a uniform microhardness distribution. The surface roughness of the walls was strongly dependent on the inclination angle of the sample relative to the building platform, with a greater wall incination angle resulting in greater wall surface roughness, as defined by the parameters Ra and Rz. These investigations of M300 maraging steel processing using L-PBF contribute to filling the existing research gap in regard to the application of this material for the fabrication of thin-walled structures.

In this study, we investigated the impact of rhenium doping on the oxidation resistance of the Ni-based Inconel 713C alloy at 1000 °C. A rhenium dopant was introduced into the Inconel 713C alloy powder using an alternative to the mechanical method, a wet chemical method based on the sol–gel process. The doped powder was consolidated by an additive method using the selective laser melting technique, which allowed the Inconel 713C:Re alloy to be obtained. The high-temperature behavior of the Inconel 713C:Re alloy was compared with the alloy without a rhenium dopant, manufactured by SLM, and with the Inconel 713C alloy in cast form. Differences in the microstructure and chemical composition of the oxide scale formed on the tested samples were observed. For the SLM-manufactured Inconel 713C alloy samples undoped and Re-doped, the oxidation process was controlled by the outward diffusion of elements like Ni, Cr, Al, and Ti with simultaneous inward diffusion of oxygen along columnar grain boundaries. Oxygen diffusion was facilitated by the columnar shape of the grains and by the defects in the form of pores and microcracks introduced during the additive manufacturing process. The rhenium dopant significantly reduced the growth of the oxide layer on the Inconel 713C alloy exposed to a temperature of 1000 °C. Based on the determined oxidation rate constants, it can be concluded that the Inconel 713C:Re alloy showed higher oxidation resistance at 1000 °C compared to the other tested samples.

This study investigates the influence of friction stir welding parameters, specifically tool rotational speed and linear speed, on the electrochemical and mechanical properties of EN AW-6082-T651 butt joints. The research encompassed microstructural analysis, surface roughness measurements, potentiodynamic corrosion tests, hardness profile measurement, and static tensile testing. Results revealed that decreasing the linear speed or increasing the rotational speed during welding intensified heat input, leading to grain growth in the weld nugget zone. The smallest grain size of 3.46 ± 1.11 µm was achieved at 1000 rpm and 250 mm/min. Surface roughness was minimized at 1250 rpm and 200 mm/min, as excessive tool feed caused irregularities. Corrosion resistance improved compared to the parent material, attributed to fine-grained structures promoting compact passive layer formation. Hardness profiling indicated the lowest values in the heat-affected zone, particularly for joints produced at 1250 rpm and 200 mm/min due to the highest heat input and precipitate dissolution. Tensile testing confirmed fracture locations in the heat-affected zone, with maximum tensile strength reaching 69

In this work, we investigated whether rhenium doping has a beneficial effect on the mechanical properties of the IN 713C alloy. The alloy powder was doped with rhenium using a chemical method and consolidated in the 3D printing. The tensile strength tests conducted at 750°C demonstrated the highest tensile strength for the IN 713C alloy doped with rhenium. The results indicate an 8

This study investigates the impact of build orientation on the corrosion resistance of CoCrWMo alloys fabricated by Laser Powder Bed Fusion (L-PBF). Samples printed at angles from 0° to 90° were characterized using SEM, XRD (with modified Williamson-Hall and Warren-Averbach analysis), and potentiodynamic polarization in Ringer's solution. The results revealed that build orientation strongly affects microstrain, dislocation density, and dislocation character, which in turn govern passive layer composition and corrosion behavior. The sample printed at 90° exhibited the highest corrosion resistance, correlating with the lowest dislocation density, minimal microstrain, and the highest fraction of screw dislocations. XPS analysis showed this sample had the most Cr-rich passive layer, with Cr₂O₃ accounting for over 60% of oxide species. In contrast, low-angle samples exhibited more edge dislocations, higher microstrain, and less protective oxide films. These findings highlight the critical role of build-induced crystallographic anisotropy and defect structure in shaping corrosion response in L-PBF-processed biomedical alloys. The study also demonstrates the utility of advanced XRD-based methods for quantifying lattice distortions and dislocation populations. Importantly, the results support sustainable design strategies by enhancing corrosion resistance through process control, reducing reliance on coatings or alloying, and promoting resource-efficient manufacturing of biomedical and engineering components.

In this work, the microstructure and degradation properties of a novel metal matrix composite composed of Mg with the addition of 1 vol. % hydroxyapatite nanopowder (Mg + 1 vol % nHAp) were evaluated. The composites in the form of discs produced using spark plasma sintering (SPS) were subjected to plastic deformation using a modified extrusion technique with an oscillating die located at the end of the extruder (called KoBo), which enables deformation without the preheating of the initial billet. The microstructure was analyzed using optical and scanning electron microscopy (SEM) with subsequent electron backscattered diffraction (EBSD) measurements. The corrosion properties were evaluated based on electrochemical and immersion tests. To assess early biological performance, cytotoxicity tests were performed. The addition of nHAp did not significantly change the corrosion rate; however, the subsequent plastic deformation greatly decreased it. Interestingly, the sample after plastic deformation without the preheating of the initial billet was characterized by the highest cell viability. Overall, the addition of nHAp improved the biological assessment of the extruded composite; however, during plastic deformation, due to the refinement of loosely adherent nHAp and the formation of bimodally distributed grain sizes, a high number of microgalvanic couples were formed, resulting in worse corrosion performance.

This study investigates the effects of Hot Isostatic Pressing (HIP) treatment on the microstructural evolution and mechanical properties of Laser Powder Bed Fusion (LPBF)-manufactured Hastelloy H. This research evaluates the trade-offs between defect elimination, anisotropy reduction, and strength retention in well-optimized LPBF components. Specimens were manufactured using optimized LPBF parameters, achieving 99.85% density, and then subjected to HIP treatment at 1160 °C/100 MPa for 4 h. The analysis includes porosity analysis, grain size measurement, crystallographic texture evaluation, and tensile tests in two principal orientations. The results show that HIP treatment provides minimal benefits for defect elimination in already high-quality LPBF material, reducing porosity from 0.15% to <0.01%—a negligible improvement that does not translate to proportional mechanical enhancement. Tensile tests show that as-built specimens exhibited orientation-dependent strength, with XY-oriented samples reaching a yield strength (YS) of 682 MPa, ultimate tensile strength (UTS) of 864 MPa, and elongation of 17%, while XZ-oriented samples showed lower strength (YS = 621 MPa, UTS = 653 MPa) but superior ductility (elongation = 47%). After HIP treatment, anisotropy was largely removed, with both XY and XZ orientations showing comparable strength (YS ≈ 315–317 MPa, UTS ≈ 682–691 MPa) and elongation (38–41%). This indicates that HIP significantly improves ductility and isotropy at the cost of reduced strength. HIP treatment effectively eliminates the anisotropy of LPBF components, achieving uniform hardness across all orientations while reducing crystallographic texture intensity from 12.3× to 3.2× random orientation. This isotropy improvement occurs through grain-coarsening mechanisms that increase the average grain size from 7.5 μm to 13.5 μm, eliminating cellular–dendritic strengthening structures and reducing hardness by 32% (254 HV2 to 170 HV2) following Hall–Petch relationships. The conducted research confirms that HIP treatment allows for modification of the microstructure of Hastelloy X alloy, which may lead to the improvement of its mechanical properties in high-temperature applications and a significant increase in the isotropy of the material.

The research investigated the influence of laser powder bed fusion (LPBF) parameters for NickelAlloy HX, a nickel-based superalloy, to achieve high-density components with superior mechanical properties. A systematic approach was employed, involving printing 40 cylindrical specimens with varying energy densities (50–240 J/mm3) to evaluate porosity, hardness, and anisotropy. Results revealed that energy density significantly influences relative density, with optimal parameters identified at 111 J/mm3 (900 mm/s scan speed, 120 W laser power). Microstructural examination revealed columnar grains aligned with the build direction in as-printed samples. The findings highlight the trade-offs between density, hardness, and microstructure in the additive manufacturing of nickel-based superalloys, providing actionable insights for industrial applications requiring specific property profiles.

This study investigates the strain hardening and dislocation structure in the surface layers of C45 steel subjected to precision grinding at various depths. The aim was to assess how different grinding conditions influence the mechanical response and defect structure of ferrite. Nanoindentation was used to evaluate mechanical properties, while X-ray diffraction analysis provided data on the microstrain, crystallite size, and residual stress. The character and density of dislocations were further examined using modified Williamson–Hall and q-parameter analysis. The results revealed that the sample ground to a depth of 2 μm exhibited the highest density of statistically stored dislocations, as well as the lowest dislocation mobility. This condition also corresponded to the highest residual stresses and the greatest share of screw dislocations, indicating intense strain localization. In contrast, deeper grinding depths resulted in lower dislocation densities and reduced the strain energy. The observed trends highlight the formation of a dislocation-rich nanostructured layer in the shallowest ground region. These findings provide new insights into the mechanisms of surface hardening in ferritic steels and demonstrate how the depth of material removal during grinding governs the subsurface microstructure and strengthening effects.

In this study, the relationship between the extrusion ratio and the corrosion resistance of pure Mg deformed using extrusion with an oscillating die (KoBo) without preheating of the initial billet was investigated. The materials investigated in this study were extruded at high deformation ratios, R1 5:1, R2 7:1, and R3 10:1, resulting in significant grain refinement from the very coarse grains formed in the initial billet to a few µm in the KoBo-extruded samples at room temperature, which is not typical for hexagonal structures. Our research clearly shows that KoBo extrusion improves the corrosion performance of pure Mg, but there is no straightforward dependence between the extrusion ratios and corrosion resistance improvement. Although it was expected that the smallest grain size should provide the highest corrosion resistance, the dislocation density accumulated in the grain interiors during deformation at the highest extrusion ratio, R3 10:1, supports dissolution reactions. This, in turn, provides the answers for the greater grain size observed after deformation at R2 7:1, where dynamic recovery prevailed over dynamic recrystallization. This situation led to the annihilation of dislocation, leading to better corrosion resistance of the respective alloy. Therefore, the alloy with the greatest grain size has the best corrosion resistance.

This paper presents a continuous severe plastic deformation (SPD) process for sheet metal called Dual Rolls Equal Channel Extrusion (DRECE) is introduced. The DRECE process achieves maximum sheet metal deformation by combining bending deformation with channel-angular shear deformation. The evolution of the microstructure and mechanical properties of the CuZn37 alloy has been experimentally investigated as a function of the number of repeated DRECE passes. The DRECE process was repeated up to four times at room temperature. As the number of passes increased, the character of the microstructure was gradually strongly deformed by intensive shear deformation. The microhardness and tensile properties changed significantly as a function of the number of repeated passes.

The results of experimental and numerical studies of plastic forming of sheets made of the difficult-to-deform Hastelloy X, a nickel-based alloy with a thickness of 1 mm, using layered elastomeric punches and steel dies, are presented in this publication. The elastomeric punches were characterized by hardness in the range of 50-90 Shore A, while the dies were made of 90MnCrV8 steel with a hardness of over 60 HRC. The principle of operating the stamping die was based on the Guerin method. The finite-element-based numerical modeling of the forming process for various configurations of polyurethane inserts was also carried out. The results obtained from numerical modeling were confirmed by the results of experimental tests. The drawpieces obtained through sheet forming were subjected to geometry tests using optical 3D scanning. The results confirmed that in the case of forming difficult-to-deform Hastelloy X, Ni-based alloy sheets, the hardness of the polyurethane inserts significantly affected the geometric quality of the obtained drawpieces. Significant nonuniform sheet metal deformations were also found, which may pose a problem in the process of designing forming tools and the technology of the plastic forming of Hastelloy X, Ni-based alloy sheets.

In this study, the possibilities of improving the mechanical and corrosion properties of Mg–4Li–1Ca processed using twist channel angular pressing (TCAP) were investigated. There was a special focus on the optimization of the TCAP parameters through analyzing how the temperature of TCAP influences the microstructural, mechanical, and corrosion properties of the alloy, and how an increasing number of TCAP passes affects these properties. It was shown that among specimens extruded with one pass, the highest mechanical properties were achieved at 180 °C. Microstructural changes were noted at higher temperatures and caused a decline in the mechanical properties. The influence of an increasing number of passes through the TCAP channel was rather minor and did not lead to significant microstructural strengthening. In contrast, the best corrosion performance was observed after four passes at 180 °C and after a single pass at 300 °C. The results of this study show that TCAP is an efficient method for the grain refinement of hcp-structured metals, lowering the costs of the plastic deformation of Mg-based alloys.

This study investigates the influence of solution treatment temperatures on the microstructure and mechanical properties of LPBF (Laser Powder Bed Fusion)-manufactured Inconel 939 alloy. The primary objectives are to assess the impact of sub-recrystallization (below recrystallization temperature) and recrystallization temperatures during solution treatment on mechanical performance under different conditions. This study validates the hypothesis concerning carbide redistribution and mechanical performance in LPBF-produced Inconel 939 parts through comprehensive analysis, including microstructure studies and tensile tests. The results indicate that higher heat treatment temperatures lead to significant changes in carbide redistribution and mechanical performance. For instance, at room temperature, the specimen with sub-recrystallization solution treatment temperature exhibited superior mechanical properties compared to both the as-built and recrystallization-temperature solution treatment specimens. However, at elevated temperatures (700 °C), a reversal in mechanical anisotropy was observed, with the vertical axis demonstrating higher tensile strength compared to the horizontal axis for all material states. Furthermore, a microstructural analysis revealed distinct changes in grain structure and precipitate distribution, particularly the migration of carbides from grain boundaries to intragranular regions. These findings underscore the importance of precise control over heat treatment parameters to achieve optimal mechanical behavior. This research provides valuable insights into optimizing LPBF processes for the Inconel 939 alloy, highlighting the need for a meticulous control of the solution treatment parameters to ensure mechanical integrity. The findings contribute to a broader understanding of material-specific responses in additive manufacturing, with significant implications for aerospace applications.

This paper presents the results of a pilot application of Powder-Bed Fusion of Metals Using a Laser (PBF-LB/M) for the fabrication of M300 (1.2709) maraging steel sheet metal bending tools. S235 steel was used as a substrate for the fabrication of bending punches. The main goal of the research was to determine the usability of such tools without heat treatment, which would contribute to the increase in the cost of tool production. Industrial tests of tools were conducted during the forming of Inconel 625 and AW-6061 T0 aluminium alloy sheets. The punches were subjected to tests of surface roughness, hardness, microstructure, porosity, and geometric quality in order to verify the quality and accuracy of tools made by the PBF-LB/M technique before and after experimental investigations in industrial conditions in a selected manufacturing company. It was found that tools with an M300 steel working layer after the PBF-LB/M process without heat treatment show suitability for bending sheet metal in a certain range of force parameters, ensuring obtaining elements after bending from Inconel 625 and AW-6061 T0 aluminium alloy sheets of the required geometric quality.

In this study, we examined the effects of an aluminization process on the microstructure and texture of Haynes 282 nickel samples fabricated using the direct metal laser sintering technique. The aluminization process involved the use of chemical vapor deposition with AlCl3 vapors in a hydrogen atmosphere at a temperature of 1040 °C for 8 h. Following the 3D printing and aluminization steps, we analyzed the microstructure of the Haynes 282 nickel alloy samples using light microscopy and scanning electron microscopy. Additionally, we investigated the texture using X-ray diffractometry. A texture analysis revealed that after the process of direct laser sintering of metals, the texture of the Haynes 282 nickel alloy samples developed a texture typical of cast materials. Then, in the aluminization process, the texture was transformed—from foundry-type components to a texture characteristic of recrystallization.