This study examines how surface roughness influences LIBS spectral quality in LPBF alloy steel. Roughness balances reflectivity, ablation threshold, and plasma effects to govern signal stability, with optimal quality at medium roughness levels.

Influence of a polymeric azetidinium salt cationic polymer as an anticorrosion agent in an acidic medium for carbon steel alloy: Practical and theoretical aspects

HighlightsThe Fe–28.6 Mn–10.9 Al alloy is BCC ferrite at temperatures between 850 and 1100 °C.β-Mn exists in the ferrite at temperatures ranging from 500 °C to 850 °C.β-Mn phase is formed as Widmanstätten side-plates.The formation of the β-Mn in BCC shows the following OR: ()β// (100)α and []β// [012]α.What are the main findings?The alloy exhibits a single BCC phase at temperatures above 850 °C.β-Mn is thermally stable between 500 °C and 850 °C.β-Mn appears as Widmanstätten side-plates that coarsen with temperature.The β-Mn in BCC shows an OR established as ()β // (100)α and []β // [012]α.What are the implications of the main findings?We clarify the precipitation behavior of β-Mn.We provide new insights into β-Mn phase stability in Fe–Mn–Al alloy.We provide information contributing to the development of high-strength, lightweight steels.The microstructural evolution and phase stability in Fe–Mn–Al alloys play a decisive role in determining their mechanical performance and potential applications. This study investigates the precipitation behavior and crystallography of the β-Mn phase in an Fe–28.6 Mn–10.9 Al (wt.%) alloy subjected to annealing at 1100 °C, followed by water quenching and subsequent isothermal holding at temperatures between 500 °C and 900 °C for 20 h. Microstructural analysis using X-ray diffraction, optical and electron microscopy revealed a single body-centered cubic (BCC) ferritic matrix above 850 °C and the formation of β-Mn precipitates with Widmanstätten side-plate morphology at lower temperatures. The β-Mn phase was thermally stable between ~500 °C and 850 °C, with the volume fraction increasing with temperature and reaching a maximum near 650 °C. The β-Mn precipitates coarsened progressively with increasing temperature and were found to be richer in Mn than the surrounding Fe-rich BCC matrix. Crystallographic analysis established an orientation relationship (OR) of ()β // (100)α and []β // [012]α, where // denotes nearly parallel alignment, signifying a semi-coherent interface between the two structures. These findings clarify β-Mn precipitation, its interfacial relationship with ferrite, and its thermal stability in high-Mn Fe–Mn–Al alloys, offering guidance for microstructural design in next-generation lightweight steels.

The cleanliness and functionalization of metal surfaces are critical factors to determining their performance in high-performance microelectronic packaging, reliable biomedical implants, advanced composite bonding, and other fields. Compared to traditional wet cleaning methods, plasma cleaning technology has emerged as a research hotspot in surface engineering due to its unique advantages, such as high efficiency and environmental friendliness. It operates under versatile conditions (e.g., power: tens of watts to several kilowatts; pressure: atmospheric to low vacuum; treatment time: seconds to minutes), enabling not only efficient contaminant removal but also targeted surface functionalization, including dramatically enhanced hydrophilicity (e.g., contact angles from >80° to <10°), significantly improved adhesion (e.g., up to 40% increase in bond strength), and modifications in surface roughness, corrosion resistance, and biocompatibility. This review systematically elaborates on the physical, chemical, and synergistic mechanisms of plasma cleaning technology as it acts on metal surfaces. It focuses on plasma cleaning applied to copper, aluminum, titanium and their respective alloys, as well as alloy steels, providing a detailed analysis of contaminant types, plasma cleaning methodologies, common challenges, surface functionalization responses, and subsequent functional applications. Furthermore, this review discusses the current challenges faced by plasma cleaning technology and offers perspectives on its future development directions. It aims to systematize the research progress in plasma cleaning of metal surfaces, thereby facilitating the transition of this technology towards large-scale industrial applications for metal surface functionalization.

The continuous pursuit of efficiency in mechanical design demands components that combine lightweight characteristics with structural strength.This study presents an integrated Computer-Aided Design (CAD) and Finite Element Analysis (FEA) workflow for the topology optimization of a mechanical component, where an L-shaped bracket was selected as a case study.The process began with the initial design and static structural analysis using SolidWorks to establish a baseline performance under typical operating loads.The model was then subjected to a topology optimization study in SolidWorks Simulation, aiming to reduce mass while maintaining structural integrity within predefined constraints. After interpreting the optimization results, the optimized geometry was reconstructed in SolidWorks, and a final validation FEA was performed on the new design.The results demonstrated a 54.74% reduction in mass compared to the original model, while the maximum von Mises stress increased by only 15%, remaining well below the yield strength of the alloy steel. This confirms the effectiveness of topology optimization in achieving substantial weight reduction without compromising key performance criteria, emphasizing its essential role in modern mechanical design and analysis.

Austempered Ductile Iron (ADI) casting technology is a combination of the smelting process, its post-furnace treatment and the heat treatment of castings. Maintaining the process parameter stability of this innovative high quality cast iron with high Tensile Strength UTS and ductility properties is the aim of a number of studies on the control of graphitization inoculation and inoculation of the metal matrix. The ability to graphitise the liquid alloy decreases with its holding in the furnace, time of pouring into moulds from pouring machines. The tendency to dendritic grains crystallization and the segregation of elements such as Si, Ni and Cu decrease the ductile properties. The austenitizing process can introduce austenite grains growth negatively affecting of the ausferrite morphology. The modifying effect of small amounts of additives on the metal matrix in steel and low alloy cast steel, well known in materials engineering, has been applied to ADI. The addition of cast iron chips, Fe-V and Fe-Nb to the liquid alloy in the first inoculation is an example of a hybrid interaction. The introduction of graphitization nucleus particles and austenite crystallisation nucleus particles resulted in a stabilisation of the ductility of ADI and an increase in mechanical properties. Grains refinement of the primary austenite and precipitation hardening of ausferrite stabilise the mechanical properties of ADI. As a result of graphitization and additive structure inoculation, graphite and ausferrite morphology is improved. The obtained results point the way to further research in the field of hybrid inoculation of Ductile Cast Iron.

Corrosion behavior of 650 MPa high strength low alloy steel in industrial polluted environments containing different concentrations of Cl−

This study utilizes bibliometric tools VOSviewer and CiteSpace to analyze the research hotspots, development trends, and emerging dynamics in the field of internal fixation materials (IFM) from 2004 to 2024. The dataset used in this study is publicly available at https://github.com/Lin1Xiao2Zhou3/VOS-CiteSpace-Datasets, and its permanent digital object identifier link is https://doi.org/10.5281/zenodo.14277420. IFM are crucial in orthopedics for fracture fixation and bone healing. Traditional metallic materials, such as stainless steel and titanium alloys, have been widely used in clinical practice due to their excellent mechanical properties. However, the biocompatibility issues of these materials limit their long-term clinical effectiveness. In recent years, research has shifted towards biodegradable materials, such as magnesium alloys and composites, to enhance biocompatibility and reduce the need for secondary surgeries. Through keyword co-occurrence and citation analysis, this study identifies key research themes, influential scholars, and leading institutions in the field. The results show that bioactive materials, mechanical properties, biodegradability, and their roles in promoting bone healing have emerged as core research priorities. Temporal trends indicate that the introduction of novel materials, advancements in composites, and the application of biomedical engineering technologies have become key directions in research. Future studies are expected to focus on personalized and intelligent designs, as well as improving biocompatibility, to meet clinical needs and improve patient outcomes. This study provides a comprehensive overview of the development of IFM, offering valuable insights for academic and clinical researchers (additional background details are available in File S1, Supplemental Digital Content, https://links.lww.com/MD/Q714 and extended results can be found in File S3, Supplemental Digital Content, https://links.lww.com/MD/Q715).

ABSTRACTRationaleLaser ablation mass spectrometry provides fast and direct chemical information of solids with high spatial resolution without the need for complex sample preparation. It has been shown that reducing the laser pulse length below picoseconds improves the quantification of chemical composition measurements of solids. This study compares the impact on chemical quantification of applying femtosecond laser ablation from IR to UV wavelengths to a steel alloy sample from NIST.MethodsA compact laser ablation ionisation mass spectrometer (LIMS), coupled to a fs laser ablation ion source with a fundamental laser wavelength of 775 nm, is used for the presented mass spectrometric results. The fundamental wavelength is frequency doubled or tripled to 387 and 258 nm, respectively. An extensive mass spectrometric campaign, comprising various laser pulse energies, was conducted using the NIST iron alloy standard reference material 664. The recorded element composition was compared with the NIST certified values.ResultsChemical composition analysis demonstrated the presence of significant chemical inhomogeneity of the NIST reference samples at spatial scales of about 10 μm, particularly in Ti and S. Large deviations identified were avoided for the presented study. A score was calculated for each of the accumulated spectra, indicating how close the measured composition reflected the certified values. The results show only minor differences between the wavelengths applied for sufficiently high irradiances.ConclusionsThese studies conducted on steel alloy NIST SRM 664 demonstrate that the impact of laser wavelength on the quantification becomes only noticeable for low irradiances. At sufficiently high laser irradiances at around 3.1 TW/cm2 and beyond, comparable calibration coefficients can be observed.

ABSTRACT Traditional models such as the equivalent strain model and the critical plane model have been widely applied to predict multiaxial fatigue life but still are continuously improved in practical engineering scenarios. To find better and more universal model, a deep symbolic regression framework is proposed to generate multiaxial fatigue life prediction models that integrate physical interpretability with high predictive accuracy through the use of a recurrent neural network and policy gradient optimization. Compared with the equivalent strain model, the maximum shear strain model, and the critical plane model, the proposed method demonstrates the superior predictive performance for pure titanium, BT9 and TC4 alloys. Furthermore, it also shows strong generalization capability in cross‐material validation involving PA38‐T6 aluminum alloy, GH4169 alloy, and S460N steel. The proposed framework provides a novel pathway for advancing the development of fatigue modeling.

The features of the technology of restoring the worn-out working surface of the cylinder liner by applying a layer of aluminum powder by cold gas-dynamic spraying followed by its treatment by microarc oxidation and the creation of a wear-resistant ceramic layer on the surface were considered. A review of studies devoted to the combined use of cold gas-dynamic spraying and microarc oxidation for the restoration and hardening of the surfaces of parts made of various materials was carried out. (Research purpose) The research purpose is increasing the durability of the cylinder liner by restoring the worn inner working surface by applying a combined coating using cold gas dynamic spraying of aluminum powder followed by its microarc oxidation. (Materials and methods) Tested the developed technology for restoring worn-out working surfaces of the GZ-195N engine liners, according to the results of which they created an installation for automated application and processing of a gas-dynamic coating and technological equipment for micro-arc oxidation. The modes of gas dynamic spraying and microarc oxidation during the restoration of the liners are given. The methodology for conducting accelerated bench comparative tribotechnical tests of full-scale samples made from restored and new liners (in the state of factory delivery) was described. (Results and discussion) The results of comparative accelerated tribotechnical tests of full-scale samples from new and restored liners of the GZ-195N diesel engine for workability and wear resistance were presented. The test results were analyzed using complex tribotechnical coupling characteristics. (Conclusions) The use of combined technology to restore worn-out liners using cold gas-dynamic spraying of an aluminum layer followed by micro-arc oxidation ensures their operability and tribotechnical properties at the level of new liners. The developed combined technology is effective for restoring cylinder liners made of gray cast iron, steel and aluminum alloys.

Introduction. Additive manufacturing (AM) technologies, particularly wire arc additive manufacturing (WAAM), offer a rapid and cost-effective approach for producing complex metal components. However, WAAM can induce anisotropy in the resulting material's physical and mechanical properties. This anisotropy must be considered in design and application to ensure reliable performance in service. The purpose of the work. This study aims to quantitatively assess the anisotropy of mechanical properties in materials produced by WAAM to enhance the reliability of components used in critical applications. Research methodology. Samples were fabricated from low-carbon alloyed steel (0.08 C-2 Mn-1 Si), stainless steel (0.04 C-19 Cr-9 Ni), and aluminum alloy (97 Al-3 Mg) using the WAAM process. These samples were then subjected to mechanical testing to determine their tensile and impact toughness and hardness. Results were compared to those of the materials in the initial state to determine the relative anisotropy of each property. Results and discussion. For 0.08 C-2 Mn-1 Si steel, the tensile strength of WAAM-fabricated samples exhibited minimal variation across different orientations, indicating relatively high isotropy (relative anisotropy of 1.3 %). A relative anisotropy of 33 % was observed for elongation, 21 % for impact toughness, and 16 % for hardness. The 0.04 C-19 Cr-9 Ni stainless steel exhibited a relative anisotropy of 15.1 % for tensile strength, 244 % for elongation, 33 % for impact toughness, and 4% for hardness. The 97 Al-3 Mg aluminum alloy showed a significant relative anisotropy in tensile strength (83.6 %) and relative elongation (513 %) due to differences in the “vertical” direction. Impact toughness exhibited only slight variations (28 %) depending on sample orientation, while hardness can be considered isotropic. In general, hardness demonstrated the lowest relative anisotropy, while elongation exhibited the highest.

Purpose: To determine the most promising materials for creating the HSR car bodies. To select the optimal welding methods for their assembly. Methods: An analysis of the properties of current and prospective metals used in the manufacture of high-speed railway car bodies by leading rolling stock manufacturers in Europe, Japan and China. Results: In the fabrication of HST car bodies, the most prevalent structures are composed of stainless steel and aluminum alloys, which are joined by various welding methods. At present, laser welding has been found the most technologically advanced method, due to its high degree of automation and the high quality of the resulting welded joints. Practical significance: The recommendations stated in the paper are intended for designers and railway car body builders to create and build the first Russian high-speed train, the “White Gyrfalcon”.

This work systematically investigated the effect of Si content on the impact-abrasive wear mechanism of medium-carbon low-alloy steels processed through different heat treatment processes, quenching and tempering (QT), austempering, and quenching and partitioning (QP). Three experimental steels with different Si contents were subjected to optimized heat treatment parameters. Microstructural characterization revealed that Si addition significantly enhanced the volume fraction and mechanical stability of retained austenite (RA), refined bainitic and martensitic structures, and suppressed carbide precipitation. The results of mechanical properties demonstrated that austempering yielded the optimal balance of strength, hardness, ductility, and toughness. Impact-abrasive wear tests showed that the 2 B-300 steel exhibited the lowest wear mass loss due to its high work-hardening capacity, deep strain-hardened layer, and low residual tensile stress. In contrast, QT and QP processes resulted in higher wear losses, correlated with high residual tensile stress and reduced RA stability. The above results underscore that Si alloying, combined with appropriate heat treatment, effectively tailors microstructural evolution and residual stress distribution, thereby enhancing impact-abrasive wear resistance for applications in mining and mineral processing equipment. This study provides a comprehensive framework for optimizing Si content and heat treatment parameters to achieve superior wear performance in medium-carbon low-alloy steels.

This study presents the development and application of a Probabilistic Fracture Mechanics (PFM) code to assess the failure probability of nuclear reactor pressure vessels (RPVs) with pre-existing cracks. RPVs, made of low alloy steel and subjected to various aging mechanisms such as fatigue and stress corrosion cracking, are especially vulnerable in the beltline region where nuclear fission occurs. A Python-based PFM code was developed to evaluate failure risk considering a single initial crack, whose size follows a log-normal distribution. The final (critical) crack size is calculated using applied design stresses and plane strain fracture toughness (KIC), which is modeled based on Nil Ductility Temperature (NDT) and neutron fluence, using IAEA and ASME recommendations. Stress input- membrane, bending, thermal, and seismic- are determined analytically using ANSYS simulation tools and Bangladesh National Building Code (BNBC) seismic guidelines. Failure probabilities are evaluated for both vertical and horizontal crack orientations, and results are benchmarked against PRAISE-JNES code outputs. The study finds that vertical cracks pose a higher failure risk, and that increased temperature and pressure significantly raise failure probability. The proposed PFM framework offers a reliable and compliant tool for probabilistic safety assessment of RPVs.

The paper presents a calculated justification for the thermal performance of exterior building walls constructed using facade mounted ventilated systems made of pultruded composite profiles. The thermal conductivity of the composite material was determined using laboratory testing in accordance with standard methods. A series of numerical thermal calculations for a typical section of a building’s facade mounted ventilated systems made of composite materials yielded values for the specific heat loss through a point discontinuity in the form of composite brackets. These results were compared with those calculated for brackets made of metal alloys (galvanized steel, corrosion-resistant steel, and aluminum alloys). The thermal performance coefficient for exterior walls constructed using facade mounted ventilated systems made of pultruded composite materials was calculated. Prospective applications for these facade mounted ventilated systems were identified.

This study investigates hot processing properties in low alloy steels containing 0.65, 1.15, and 1.65 wt% Mn. Stress–strain curves, hot processing maps, and microstructures to clarify how Mn governs workability is analyzed. The 0.65% Mn steel shows abnormal grain growth and insufficient dynamic recrystallization (DRX) at high temperatures, while deformation at intermediate temperature and moderate strain rate yields a stable, refined microstructure. The 1.15% Mn steel shows superior hot processing properties at intermediate temperatures and medium to high strain rates. The 1.65% Mn steel displays pronounced solute drag and elevated stacking‐fault energy (SFE), which favor dominant dynamic recovery (DRV) and suppress DRX, higher strain rates are required to avoid flow‐instability regions identified in processing maps. Microstructural analysis at 1090 °C and 1.0 s −1 shows that the 1.15% Mn steel forms fine, equiaxed recrystallized grains and achieves a high fraction of high angle grain boundaries. Thereby delivering the best microstructural uniformity and processing stability. Overall, Mn modulates austenite stability, SFE, and solute drag, thereby controlling the DRX‐DRV competition and delineating the hot processing window. Accordingly, Mn‐specific hot processing schedules is proposed to concurrently optimize processing stability and mechanical properties.

Methodological approaches to determining the suitability of dispersed non‑ferrous metal oxides generated at petrochemical plants for steel alloying

Carbon steel casing material in high-temperature deep geothermal wells can be prone to severe corrosion and premature failure due to the oxidation capacity of H2O, H2S, CO2, and more corrosive species in geothermal fluid. Due to the higher temperature and pressure and phase state of fluid in high-temperature deep geothermal wells, the rate and extent of corrosion can be expected to be different than in low-temperature geothermal wells. To reduce the extent of corrosion damage and corrosion rate, and increase the lifetime of geothermal wells, one mitigation method is to clad the internal surface of the geothermal casing with a more noble, corrosion-resistant material. Conventional cladding, however, has been an expensive and time-consuming process up to the current date, but recently, a more economical and productive method has been established, i.e., EHLA cladding. In this study, a 14-day corrosion performance test was conducted on stainless steel and nickel-based alloy clads on a carbon steel substrate in a 262 °C and 95 bar geothermal well in the Hellisheidi geothermal field (SW Iceland). Samples were partially or fully cladded, and some samples were stressed to investigate the clads’ susceptibility to general corrosion and stress corrosion cracking, as well as the substrate’s vulnerability to galvanic corrosion. Corrosion analysis of pure carbon steel substrate was also investigated for comparison. Samples were microstructurally analysed with SEM, and chemical analysis was performed with EDX. The results indicated that the clad materials have good corrosion resistance in the geothermal environment tested, suggesting that EHLA cladding is a more feasible option for strengthening the corrosion resistance of geothermal casing and equipment.

Wood has been one of the most widely used sustainable materials for millennia, but its limited mechanical properties and formability have restricted its application in diverse structural contexts. In this study, we elucidate the mechanisms governing the micromechanical behaviors of wood and the strengthening effects achieved through room-temperature hydroplasticization. This process transforms wood into ultra-strong, self-densified structures with customizable shapes, driven by system deformation and energy dissipation. These effects are governed by the interplay between polymer matrix elasticity and interfacial sliding response. Notably, the hydroplasticization method enables the attainment of a high flexural strength (483 MPa), surpassing that of mechanically compressed wood and traditional materials like steel and aluminum alloys. These findings introduce new possibilities for developing complex load-bearing structures that are previously unachievable with conventional wood.