The work-hardening behavior of refractory high-entropy alloy (RHEA) and its influence on the corrosion resistance of the machined surface have been investigated. The results showed that the work-hardening degree exhibited an increase in cutting force when the feed rate increased from 0.032 mm/r to 0.1 mm/r. As the work-hardening degree of the RHEA increased, the maximum hardness and the work-hardening thickness increased gradually, reaching 586.2 HV and 580 μm, respectively. And the surface roughness decreasing from 0.8 μm to 0.66 μm, then increasing from 0.66 μm to 1.013 μm. In order to investigate the mechanism of work hardening on the microstructural evolution of the RHEA, the microstructure of the superficial layer and the matrix was studied. The results indicated that the dendrite proportions of the superficial layer increased from 103.58
The traditional carbon‑based ironmaking route is approaching its limit in further reducing CO2 emissions. To achieve deep decarbonization of the steel industry is a critical challenge, and to address this issue, this study proposes a dual‑route carbon–hydrogen hybrid metallurgical process (DRCHMP), which integrates the conventional blast furnace–basic oxygen furnace (BF‑BOF) route with a hydrogen shaft furnace–electric arc furnace (SF‑EAF) route. Based on industrial metabolism theory, a multi‑dimensional model of material flow, energy flow, and carbon emissions is developed and optimized via a genetic algorithm. Under a crude steel yield of 8.4 Mt, the carbon emission intensity of the traditional carbon metallurgical route is 2239.24 kg CO2/t. In comparison, the DRCHMP process achieves an intensity of 1135.57 kg CO2/t, corresponding to a reduction of approximately 49
The dynamic modulation mechanisms of second-phase particles on crack propagation in an Al-2.78 γ _S by increasing crack path tortuosity, thereby elevating the critical fracture stress. Upon exceeding the critical value, a sudden increase in microcrack size α leads to a sharp drop in fracture strength. This study provides direct experimental evidence for understanding the toughening mechanisms of second-phase particles and offers a theoretical basis for the strength-toughness design of Al-Cu alloys.
Magnesium (Mg) alloys are viable candidates for lightweight structural materials application in aerospace, automotive, and defense industries. However, their widespread application is limited by low ductility due to the dominance of basal slip. Mg-Y alloys have been actively studied because of their enhanced ductility and non-basal slip. Nonetheless, the mechanisms underlying mechanical behavior remain unresolved due to complex interactions among grains and grain boundaries in polycrystalline Mg alloys. In this study, an in situ tensile test was performed on a polycrystalline Mg-1 wt.
The work is devoted to a current problem of blast furnace (BF) production, which consists of the need to improve the environmental component of the metallurgical industry, which is solved in an economically feasible way by reducing the production of sinter for BFs and increasing the composition of pellets in charge, which are produced with significantly less anthropogenic pressure and carbon footprint. The main objective of the study is to develop the main technical and technological solutions for a relatively fast transition of iron-smelting technology to an increased or 100
The main purpose of this experimental study is to resolve the challenges in assessing the cumulative impact of input parameters on the outcome of friction stir spot welding (FSSW) for AA2024-T4 and C10200 products. The proper range of input parameters, namely tool penetration rate (TPR), tool plunge depth (TPD), and tool rotational speed (TRS) play a crucial role in the maximum lap shear load (Pmax) of the strongly bonded products. To address the current issue, a machine learning (ML) model, specifically Extreme Gradient Boosting (XGBoost), was used to anticipate the outcome with good predictive capability. After hyperparameter optimization using GridSearchCV, the XGBoost model achieved a coefficient of determination (R2) of 0.8803, a mean squared error (MSE) of 46,389.893 N2, and a mean absolute error (MAE) of 215.158 N, demonstrating improved predictive capability in capturing the nonlinear relationship between the process parameters and the Pmax. Raising the Pmax is critical for improving joint strength. The model correctly identified key process parameters influencing critical response. The high-angle grain boundaries (HAGBs) are discovered at the interface of the stir zone (SZ) and the thermomechanical affected zone (TMAZ). Subsequently, a mixed characterized orientation of HAGBs and low-angle grain boundaries (LAGBs) are identified between the interface of the heat-affected zone (HAZ) and the TMAZ using EBSD analysis.
This study investigates the occurrence state and migration behavior of F, K, and Na in an industrial BF processing high-fluorine Bayan Obo ore. Comprehensive characterization using XRF, XRD, and SEM-EDS, coupled with a quantitative mass balance analysis, was performed. Results show that alkali metals primarily enter as silicates, while fluorine enters mainly as CaF2 in sinter. The slag serves as the primary sink, fixing 75.26
Topological insulators (TIs) constitute a class of modern functional materials regarded as a foundation for spintronics, energy-efficient electronics, thermoelectrics, and quantum technologies. To discover and develop alternative materials with tunable properties, a comprehensive experimental investigation of phase equilibria in the SnTe–PbTe–Bi2Te3 system was conducted for the first time to our knowledge. A solid-phase equilibrium diagram at 500 K, a liquidus surface projection, and some isopleth sections were constructed. The types and coordinates of invariant and monovariant equilibria in the system were identified. Continuous and wide-range solid solution series based on AIVTe·nBi2Te3 homologous compounds with TI properties were identified and characterized. It was established that continuous solid solutions are formed along the SnBi2Te4–PbBi2Te4, SnBi4Te7–PbBi4Te7, and SnBi6Te10–PbBi6Te10 sections. Wide-range solid solutions based on tetradymite-type compounds Sn2Bi2Te5 and Sn3Bi2Te6 were observed along the Sn2Bi2Te5–"Pb2Bi2Te5" and Sn3Bi2Te6–"Pb3Bi2Te6" sections. The unlimited solid solutions of the boundary quasibinary SnTe–PbTe system extend into the composition triangle. A wide homogeneity region is observed based on Bi2Te3. The primary crystallization fields and homogeneity regions of all phases, along with their crystal lattice parameters, were determined. The novel nonstoichiometric phases identified in this study are promising candidates for TIs in low-energy electronics applications.
The use of in situ experimental methods for real-time observation of the propagating solid-liquid interface during solidification is key to predicting and controlling solidification microstructures. In situ observation of metal alloy solidification can be achieved using X-ray imaging, as metal alloys exhibit sufficient X-ray transmission. The progress made in laboratory X-ray sources and X-ray detectors enables the study of solidification using in situ X-radiography with compact, portable apparatus. In situ observation of solidification aboard microgravity platforms such as sounding rockets and parabolic flights has been successfully performed using X-radiography over the last decade. However, steady-state conditions could not be reached because of the limited microgravity duration accessible via these platforms and the use of the power-down technique to cool the sample. An X-ray facility for the International Space Station (XRF-ISS) is currently being developed by the European Space Agency (ESA) to overcome this limitation. XRF-ISS will enable multiple experiments so that statistical variations can be studied by varying the principal parameters by design. We report on Breadboard directional solidification experiments conducted in “Experiment Unit 1” (EU-1) for aluminum alloys. We discuss the technical performance of the setup and the preliminary scientific insights gained. More specifically, we report on analyses of the temperature field and grain structure formation based on image sequences recorded during power-down solidification experiments. Furthermore, we discuss the impact of residual fluid flow on solidification triggered by sample pulling. The possibilities offered by this new device are also presented and discussed.
As the main solid waste produced by coal-fired power plants, coal fly ash (CFA) is considered to be a potential high-value aluminum resource due to its high content of alumina (about 10–50
Electroless Ni-P-SiC nanocomposite coatings were systematically optimized by varying three critical parameters: SiC nanoparticle concentration (1 g/L, 3 g/L, and 5 g/L), cetyltrimethylammonium bromide (CTAB) surfactant concentration (50 mg/L, 500 mg/L, and 1000 mg/L), and post-deposition heat treatment (as-deposited versus 400°C annealed). The coatings were evaluated using microstructural analysis [scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD)], mechanical characterization (microhardness, nanoindentation with H3/E2 plasticity index), and tribological testing (pin-on-disk wear and friction coefficient measurements). Results showed that 1 g/L SiC resulted in the best nanoparticle dispersion, while higher concentrations led to agglomeration and surface roughness. CTAB surfactant at 50 mg/L significantly enhanced SiC incorporation (3.2 wt.
This study presents a physics-based data-driven machine learning framework for real-time FeO prediction in industrial iron ore sintering processes using magnetic induction (∆L) and tonnage per hour (TPH) as the primary process variables. Industrial sensor data collected under varying operating conditions exhibited strong nonlinear characteristics, making conventional regression approaches insufficient for accurate prediction. Multiple machine learning models, including XGBoost, SVR, Neural Network, and Random Forest, were evaluated for FeO prediction. Among them, the Random Forest model achieved the best prediction performance with an R2 value greater than 90
High-temperature curing and dynamic disturbances jointly influence the stability of cemented tailings backfill (CTB) in deep mining. CTB specimens cured at 20–50°C for 7–100 days were tested using a split Hopkinson pressure bar, together with energy analysis, NMR, SEM, and constitutive modeling. Dynamic strength, elastic modulus, and energy absorption density showed a rise–peak–decline trend, with optimum performance at approximately 40°C and 28–60 days. Microstructural observations revealed that moderate heating promoted hydration and pore refinement, whereas excessive temperature or prolonged curing induced pore coarsening and microcracking, resulting in strength degradation and brittle failure. A dynamic damage constitutive model incorporating initial porosity and Weibull statistics was further developed to describe the full stress–strain response and to capture the coupled effects of curing temperature and curing time. The results clarify the pore evolution–energy dissipation–strength response mechanism of CTB and provide guidance for backfill design in deep, high-temperature mines.
In this study, a short-process route consisting of arc spraying, first annealing, small-reduction rolling, and second annealing was sequentially adopted to prepare copper coatings. The results show that the as-sprayed copper coating exhibits the worst corrosion resistance in a 3.5-wt.
The microstructure of a commercially produced AA1100 aluminum matrix composite reinforced with 25 vol.
Transition metal tin-chalcogenide (TMTC) monolayers are systematically investigated as two-dimensional anode materials for Li+, Na+, and K+-ion batteries using density functional theory calculations. Adsorption and Bader charge analyses reveal stable accommodation of all three alkali ions, with Li+ exhibiting the strongest binding energies and the highest charge transfer (up to − 0.77 e in Mo2S2Sn), while K+ displays the weakest interaction at elevated coverages. Electronic structure calculations confirm that the intrinsic metallic conductivity of TMTC monolayers is fully retained upon ion adsorption. Climbing-image nudged elastic band simulations disclose remarkably low minimum diffusion barriers of 0.23–0.31 eV for Li+, 0.118–0.149 eV for Na+, and 0.037–0.246 eV for K+. Gibbs free energy profiles remain negative for Li+ and Na+ up to the highest loading (24 ions per cell), enabling theoretical capacities as high as 560 mAh g−1 (Mn2S2Sn) and 430 mAh g−1 (Mo2S2Sn and Nb2S2Sn), with average open-circuit voltages in the desirable 0.1–1.0 V range. In-plane strain remains moderate and gradual for Li+ and Na⁺ (< 9
