This study aims to enhance the accuracy of detecting defects on metal surfaces by proposing a lightweight metal surface defect detection network (LiMS-Net). The backbone of LiMS-Net incorporates a residual synchronous convolutional block feature extraction module that utilizes multi-scale convolution kernels. Features are concurrently processed using these multi-scale convolution kernels. In the neck stage, a Conv-MLP module that extracts global image features. This module is further enhanced by shift operations that improve information interaction among different regions of the features. To further enhance feature interaction across different scales and improve detection accuracy, a cross-scale feature fusion block is proposed. This approach alleviates feature loss issues caused by extensive feature processing. This study employed the advanced object detection methods and conducted comparative experiments using publicly available defect databases. Compared to the advanced object detection methods, LiMS-Net demonstrated superior performance across all databases while utilizing fewer parameters.

Accurate prediction of the temperature field is crucial for controlling the duplex microstructure in additive manufacturing of 2205 duplex stainless steel. Conventional numerical methods are limited by high computational cost, data-driven approaches often lack physical interpretability, and conventional physics-informed neural networks show restricted spatiotemporal modeling capability. A physics-informed encoder–decoder network with skip connections and convolutional gated recurrent units is developed to predict transient temperature evolution. The framework combines an encoder–decoder architecture based on convolutional neural networks with skip connections, while the encoder further incorporates convolutional gated recurrent unit layers to enhance spatiotemporal feature learning. Physical laws of heat transfer are incorporated into the loss function to maintain consistency with thermodynamic principles. The model attains a mean absolute percentage error of 1.37

This study investigates the effects of porosity (0%, 11%, 19.6%, 28.3%) on the discharge behavior and corrosion resistance of 1060 Al alloy anodes in 4 M NaOH. The 19.6% porosity sample exhibits optimal comprehensive performance: polarization resistance of 22,253 Omega & centerdot;cm(2), corrosion current density of 2.793 & times; 10(-3) mA & centerdot;cm(-2), stable discharge plateau and minimal voltage decay over 2-40 mA & centerdot;cm(-2), and uniform corrosion morphology. This porosity achieves an optimal balance between effective reaction interface expansion and uniform current distribution, providing experimental evidence for structural design of low-cost Al-air battery anodes.

Titanium bipolar plates (Ti-BBPs) typically corrode and form a high-resistivity passive film within the proton exchange membrane fuel cell (PEMFC) environment. Enhancing BPPs' corrosion resistance and electrical conductivity can effectively improve PEMFC performance. In this study, CrN and CrTiN coatings were deposited onto bare titanium (Ti) surfaces via cathodic arc physical vapor deposition, respectively. The effects of these coatings on the corrosion behavior, hydrophobicity, and surface conductivity in a simulated cathode environment were systematically investigated by electrochemical testing and surface analysis. After deposition of CrN and CrTiN coatings, the corrosion current density (icorr) of the Ti-BPPs decreased from 2.26 x 10-5 A center dot cm- 2 to 1.13 x 10- 8 A center dot cm- 2, and to 1.38 x 10- 7 A center dot cm- 2, respectively. This reduction is due to the superior chemical inertness and high density of the CrN and CrTiN coatings. Further, they effectively hinder electron transfer and consequently impede electrochemical corrosion. Mott-Schottky results revealed that the CrN coating behaved as a p-type semiconductor, while the CrTiN coating exhibited p-type semiconductor behavior at low potentials and n-type behavior at high potentials. Due to limited carrier transport caused by the dense passive film, the coating's carrier density decreased by one to two orders of magnitude. Following the potentiostatic polarization (PSP) test, the interfacial contact resistance (ICR) of bare Ti increased from 15.21 mS2 center dot cm2 to 51.96 mS2 center dot cm2. In contrast, the ICR of CrN and CrTiN coatings decreased from 51.96 mS2 center dot cm2 to 4.9 mS2 center dot cm2, and to 1.32 mS2 center dot cm2.

TC4 alloy, widely employed in critical moving components, is susceptible to severe wear under elevated temperatures. Fabricating composite coatings on TC4 alloy through surface modification techniques is an effective strategy for enhancing its wear resistance. However, a systematic investigation of the relationship between coating composition, processes, microstructure, and properties is currently lacking. To address this issue, the novel wear-resistant TiCrNiVNb/TiCx refractory high-entropy alloy (RHEA) composite coatings with an average thickness of 1.3-1.5 mm are fabricated via laser cladding in this study, and their process optimization, microstructure evolution, mechanical properties, and tribological behavior are investigated systematically. Results demonstrate that a robust metallurgical bond is achieved between the coating and substrate at optimized process parameters. As the content of TiC increases, the nucleation drive force of carbides is enhanced, and the precipitation of Laves phase is suppressed. The multiple strengthening effects synergistically result in a 2.41-3.02 fold increase in the microhardness of coatings, compared to the substrate. However, an excessive addition of TiC causes severe agglomeration and exacerbates abrasive wear. Notably, the coating with 20 wt% TiC exhibits the lowest wear rates: 9.86 & times; 10-7mm3/N center dot m at room temperature and 7.57 & times; 10-6 mm3/N center dot m at 600 degrees C. The values correspond to reductions of 98.95% and 93.85%, respectively, compared to the substrate. These superior tribological properties are attributed to the synergistic effect of a homogeneous and dense hard phase network, and a glaze layer with dynamic regeneration and self-healing features. This study provides a new material system and a systematic theoretical basis for the development of high-performance coatings for titanium alloys.

The thermomechanical response and microstructure evolution of a bimodal Ti-6Al-4V alloy are investigated by isothermal compression tests within alpha+beta phase region. Intensified flow softening, primarily driven by adiabatic heating and microstructure evolution, is observed at lower temperatures or higher strain rates. Microstructural analysis demonstrates that elevated temperature, strain, and strain rate collectively accelerate the alpha ->beta phase transformation, while large deformation coupled with higher temperatures or lower strain rates facilitates the spheroidization of lamellar alpha phase (alpha L). A physical-based constitutive model is developed, incorporating four key mechanisms: (1) dislocation changes in each phase through work hardening, dynamic recovery, spheroidization of alpha L phase, and dynamic recrystallization; (2) the reduction of Hall-Petch strengthening; (3) adiabatic heating effects; and (4) variations in beta phase content. This model can successfully predict flow stress for bimodal Ti-6Al-4V within alpha+beta phase region, confirming its effectiveness in optimizing deformation and forming parameters for this alloy.

Electrochemical characterization was employed to analyze the influence of F- on the performance of CrTiNcoated titanium bipolar plates (Ti-BPPs). The experiments were conducted in a simulated proton exchange membrane fuel cell (PEMFC) environment that used 0.5 M H2SO4 containing varying concentrations of F- at 70 degrees C. As F- concentration escalated from 0 to 10 ppm, electrochemical characterization revealed an increase in icorr from 9.95 & times; 10- 8 to 7.25 & times; 10- 7 A cm- 2. Electrochemical impedance spectroscopy (EIS) analysis demonstrated marked attenuation of both |Z| and phase angle within the low-frequency domain (0.01-1 Hz). MottSchottky result investigated that the carrier density within the passive film rose in the electrolyte. These collective observations consistently demonstrate accelerated corrosion kinetics and diminished protective capacity of the coating under elevated F- concentrations. A progressive increase in the severity of corrosion was observed on the coating surface with rising F- concentration, characterized by a transition from surface dissolution to the development of corrosion pits. Upon exposure to 10 ppm F-, the corrosive attack intensified, resulting in the formation of deeper pits and a slight thinning of the coating layer. Additionally, the underlying corrosion mechanisms were further elucidated using X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometry (ICP-MS). Results suggest that the formation of soluble complexes between F- ions and the passivation layers (TiO2 and Cr2O3) on the coating surface significantly compromises the protective capability of the passivation layers.

The deformation mechanisms of coarse and fine grains in a bimodal-structured Mg-Gd-Y-Zn-Zr alloy and its influence on work hardening and fracture behavior were systematically investigated through in-situ EBSD tensile test at room temperature. Quantitative analysis of slip traces revealed that fine grains with random orientations accommodated plastic strain through basal dislocation slip and grain rotation in deformation stage I (0%-4%). In subsequent deformation stage II (4%-10%), coarse grains with basal orientation accommodated plastic strain through prismatic dislocation slip. In the later stage of plastic deformation, the heterogeneous deformation-induced (HDI) stress at the coarse/fine grain interface promoted the activation of additional non-basal dislocation slip. The improved Hall-Petch relationship, combined with Schmid factor analysis, demonstrated that coarse grains can improve the yield strength of bimodal-structured alloy due to the synergistic contributions of strong basal texture and intragranular lamellar LPSO phases. The heterogeneous deformation between coarse and fine grains induces significant back stress and activates multiple dislocation slip modes, which together enhance work hardening capacity and suppress strain localization. The coarse grains also exhibit crack blunting and deflection effects that effectively impede crack propagation, increase energy absorption during fracture, and delay final failure. These findings provide valuable insights for the microstructural design of bimodal-structured magnesium alloys.

The mechanical integrity and long-term environmental durability of adhesively bonded joints involving coldrolled and galvanized steel sheets are critical for assessing the reliability of multi-material automotive structures. This study presents a combined experimental and numerical analysis to elucidate the degradation mechanisms of these joints, both before and after hygrothermal aging, using butt, shear, and double cantilever beam (DCB) joint configurations. A systematic evaluation was conducted on the influence of substrate thickness, yield strength, and surface condition via mechanical testing and finite element modeling. The results elucidate the mechanistic roles of these factors on adhesive layer performance, with validation using single-lap joints confirming that surface condition dominates the degradation under hygrothermal aging more significantly than substrate thickness or yield strength. The research methodology encompassed two key components: firstly, quasistatic tensile tests to characterize essential adhesive properties, including elastic modulus, shear strength, and mode I fracture energy which calibrated a cohesive zone-based finite element model for simulating damage progression. This model demonstrated high fidelity, with a maximum average relative error of merely 10.8% in peak load. Secondly, hygrothermal aging tests yielded the adhesive's moisture diffusion coefficient, saturated moisture content, and coefficient of hygroscopic expansion (CHE). Implementation of a degraded cohesive zone model that incorporated these aged properties successfully captured the concomitant reduction in stiffness and strength, with a maximum average error of 14.5% in peak load prediction. This integrated approach effectively predicts failure under coupled hygrothermal-mechanical loading, thereby providing a theoretical basis for the design of reliable multi-material joints in automotive applications.

The AA7075 holds significant importance in the aerospace field. Understanding its microstructure evolution and constitutive relationships during warm deformation is crucial for optimizing forming processes. To this end, isothermal compression experiments were conducted at different temperatures and strain rates to analyze their flow stress behavior. The microstructure evolution was characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Microstructural analysis confirmed that dynamic recovery constitutes the predominant softening mechanism under warm forming conditions. The results indicate that flow stress is highly sensitive to deformation parameters, decreasing with increasing temperature and rising with increasing strain rate. To accurately describe the flow behavior, two distinct constitutive models were formulated: (1) a phenomenological Hensel-Spittel-Garofalo (HSG) model; (2) a novel hybrid machine-learning model that innovatively integrates the Harris Hawks Optimization (HHO) algorithm with an LSTM model. Both constitutive models demonstrate reasonable predictive accuracy. In comparison, the HHO-LSTM model demonstrated a superior ability to capture complex nonlinear relationships, achieving highly precise predictions of flow stress across the full range of deformation conditions tested in this work. The hybrid machine-learning model proposed in this study provides a highly accurate method for describing and predicting the flow behavior of the AA7075 during warm forming, offering a powerful predictive tool for engineering applications.

This study systematically investigates the effects of different rolling methods and single-pass reductions on the microstructure and mechanical properties of the near-beta titanium(Ti) alloy Ti-55511 under a fixed total deformation of 80%. Four sample groups were prepared using unidirectional and cross rolling processes with varying pass numbers and single-pass reductions. Experimental results show that for unidirectional rolling, a larger single-pass reduction effectively reduces dislocation density and promotes the formation of DRX grains, thereby increasing the elongation from 16.88% to 20.3% without compromising strength. This also improves sample stability, reduces the number of rolling passes, and effectively controls costs. However, when combined with cross rolling, deformed grains appear, indicating that cross rolling requires a larger single-pass reduction to reach the DRX threshold for grain refinement. Due to its higher dislocation density, cross rolling leads to greater hardness. All four sample groups introduced different dislocation densities, which subsequently affected the morphology of the secondary alpha phase precipitated during aging treatment. The cross rolling-High reduction sample, with lower dislocation density, exhibited finer precipitates and higher hardness. cross rolling, with its higher dislocation density, introduced near-90 degrees alpha phase variants, accelerating secondary phase precipitation. This study provides a theoretical basis for using larger single-pass reductions in the rolling processing of near-beta Ti alloys and proposes a cost-effective optimization strategy suitable for industrial applications.

Eutectic high entropy alloys (EHEA) such as AlCoCrFeNi2.1 exhibit unique mechanical properties, including higher strength and ductility compared to single-phase solid solution high entropy alloys (HEAs). However, their high Co content limits their engineering applications. In this work, the corrosion behavior of cost-effective AlCrFeNi HEAs, specifically AlCrFeNi3.1 and AlCrFe2Ni2.1, in a 0.5 M H2SO4 environment is systematically studied by electrochemical methods. Furthermore, the results are compared with those of AlCoCrFeNi2.1 EHEA. The findings demonstrate that both the AlCoCrFeNi2.1 EHEA and cost-effective AlCrFeNi HEAs, namely AlCrFeNi3.1 and AlCrFe2Ni2.1, consist of (Co)CrFeNi-rich face-centered cubic (FCC) and NiAl-rich body-centered cubic (BCC)/B2 phases. The AlCrFeNi3.1 alloy has excellent passivation behavior, followed by the AlCoCrFeNi2.1 and AlCrFe2Ni2.1 HEAs. The high Cr/Al ratio of the BCC/B2 phase in the AlCrFeNi3.1 alloy decreases the formation of Al hydroxides/oxides in the complex passive film, which enhances passivation and leads to a thicker passive film on the alloy surface. Specifically, the Al hydroxides/oxides reduce corrosion resistance, while Cr serves a crucial protective function. These insights significantly enhance our understanding of the electrochemical behavior of cost-effective AlCrFeNi HEAs subjected to environment-induced degradation, providing valuable guidance for the development of innovative protective materials in engineering applications.

Some studies have reported the microstructure evolution of nickel-based superalloys during isothermal forging (IF). However, most of them have not taken into account the microstructure evolution during the preheating stage in manufacturing processes. Investigating the microstructure evolution mechanisms during preheating of nickel-based superalloy can provide a more accurate characterization of the initial microstructures prior to IF. In this study, the evolution of grain structure, participation phase, and twins in a hot extruded nickel-based superalloy are examined during heat treatment at the temperature range of 1050~1140 °C and 5~180 min. Also, the interaction mechanisms among the above microstructures are analyzed. Experimental results demonstrate that higher temperature significantly accelerates the dissolution of the primary γ' (γ'p) phase and grain growth. At 180 min, the average grain size rapidly grows from 4.59 μm at 1080 °C to 14.09 μm at 1110 °C. In contrast, the impact of holding time on the microstructure diminishes after 30 min. At 1080 °C, the average grain size grows from 2.52 μm at 5 min to 4.95 μm at 30 min, after which it remains relatively stable. Initially, the γ'p phase hinders grain boundary migration and inhibits grain growth. However, its complete dissolution at high temperatures significantly promotes grain growth. Careful selection of preheating temperature can mitigate rapid grain growth before forging. Additionally, twins not only refine grains through nucleation and segmentation, but also hinder grain boundary migration in regions with high dislocation density, thereby alleviating grain growth. A model detailing the dissolution of the γ'p phase during preheating is developed, with a correlation coefficient and average absolute relative error of 0.9947 and 9.15%, respectively. This model provides theoretical support for optimizing preheating temperatures and estimating initial microstructures prior to IF.

This research has undoubtedly offered valuable insight into the correlation of grain refinement and crystallographic texture with the electrochemical properties of the cost-effective Fe40Ni25Cr25Mo5Al5 high-entropy alloy in a 0.5 M H2SO4 solution, successfully processed through the cyclic closed-die forging (CCDF) technique for up to six passes. The findings revealed that the high strains imposed during CCDF processing, along with the uniform distribution of extremely fine grains, significantly decreased the corrosion current density of the alloy from 1.05 to 0.75 mu A/cm(2). Moreover, the presence of high-intensity {011} orientations, such as the Brass {011}<211> and P {110}<221> components in the CCDF-processed alloy, provided ideal conditions for developing oxide passive films with superior protection properties compared to the as-homogenized alloy. Consequently, these findings open new avenues for the exploration of the crystallographic-orientation-dependent electrochemical properties in the corrosion performance of high-entropy alloys.

To mitigate damage-induced cracking in GH738 superalloy during hot deformation, the interplay between thermomechanical parameters (temperature, strain rate, stress triaxiality) and damage mechanisms is systematically investigated through integrated experimentation and multiscale modeling. High-temperature notched tensile tests combined with fracture morphology analysis reveal three critical dependencies: elevated temperatures accelerate void coalescence via gamma ' phase dissolution and reduced dislocation pinning; lower strain rates enhance void growth through stress relaxation; and decreased stress triaxiality promotes self-constriction effects, refining dimple distribution while intensifying necking. A micromechanics-enhanced Gurson-Tvergaard-Needleman (GTN) model incorporating gamma '-sensitive void-growth suppression is developed, where dense gamma ' distributions impede void growth via bypass-dominated dislocation interactions. Finite element validation demonstrates excellent accuracy in predicting fracture behavior across diverse thermomechanical conditions. This gamma ' phase-informed damage framework enables precise control of void evolution during hot forging, providing a critical tool for optimizing process parameters to suppress damage in gamma '-strengthened superalloys.

Herein, the effect of Nb content on the microstructure and electrochemical performance of cost-effective [FeNi]75- xCr15Mn10Nbx (x = 0, 5, 10 at%) high-entropy alloys (HEAs) in a 0.5 M H2SO4 environment was investigated. Upon the introduction of Nb into the [FeNi]75Cr15Mn10 alloy, the microstructure changed from a single face-centered cubic (FCC) solid solution to the dual-phase structures with FCC and [FeNiNb]-rich dendrites ([FeNi]70Cr15Mn10Nb5 and [FeNi]65Cr15Mn10Nb10 alloys). Also, the increase in Nb concentration leads to an increase in the [FeNiNb]-rich phase that ensures a greater formation of a stable and thicker passive oxide film. The findings emphasize the introducing Nb content was an effective strategy for improving the corrosion resistance of the cost-effective FeNiCrMn HEAs.

6061 aluminum alloy is extensively utilized in deep-sea mining applications due to its corrosion resistance, light weight, and excellent processability. This study systematically investigates the effects of single-stage aging (SSA), dual-stage aging (DSA), and retrogression re-aging (RRA) treatments on solution-treated die-cast 6061 aluminum alloy to enhance the balance between mechanical and corrosion performance. Microstructural characterization is conducted using transmission and scanning electron microscopy, along with mechanical and electrochemical testing. The results indicate that peak-aged SSA maximizes strength through dislocation shearing induced by beta '' precipitates, while the presence of continuous grain boundary precipitates and wide precipitate-free zones (PFZs) significantly compromises corrosion resistance. In contrast, DSA and RRA treatments produce discontinuous precipitates with narrowed PFZs, leading to a marked improvement in corrosion durability. Notably, the optimized RRA process retains the peak-aged strength while achieving near-optimal corrosion resistance, establishing it as the superior solution for demanding deep-sea applications that require integrated performance.

This research provides insight into the effect of strain path-dependent texture evolution on the electrochemical behavior of nanostructured AA2024 aluminum alloy in a phosphate buffer solution (pH = 8.3). To achieve this, AA2024 alloy sheets were processed using two methods: accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB), i.e., rotating the sheets 90 degrees around the normal direction (ND) axis between each cycle. The ARB-processed AA2024 alloy exhibited a pancake-shaped structure and included texture components of Copper {112}<111>, Brass {011}<211>, P {110}<221>, and S {123}<634>. Meanwhile, the CARB-processed AA2024 alloy had extremely fine and equiaxed nano-grains (< 100 nm) and texture components of S {123}<634>, Brass {011}<211>, Goss {011}<100>, Rotated Cube {001}<110>, and P {110}<221> after eight cycles. Electrochemical studies demonstrated an increase in corrosion current density due to high imposed strains in the ARB route, which in effect made the conditions of passive layer formation more difficult and lowered the corrosion resistance. Additionally, achieving a more uniform distribution of extremely fine grains and {011} orientation textures such as Brass {011}<211>, Goss {011}<100>, and P {110}<221> texture components in the CARB route, provided ideal conditions for forming oxide passive films with superior protection properties compared to ARB. These unique findings can contribute to the broader application of crystallographic-orientation-dependent electrochemical behavior of alloys in the field of corrosion management.

This study focuses on the single crystal （SC） superalloys CMSX-4 and DD5， designing and fabricating a SC test plate casting with five distinct stages. Castings with the same crystal orientation are selected to investigate their recrystallization （RX） behavior after solution heat treatment at 1300 ℃ for 2 h and 1310 ℃ for 4 h. The results indicate that CMSX-4 exhibits a stronger tendency for RX compared to DD5. Following a solution heat treatment at 1300 ℃， the CMSX-4 SC test plate displayed RX at the lower corners of 2-5 stage platforms， with the extent of RX expanding as the solution heat treatment temperature rose. Conversely， no RX was detected in the DD5 SC test plate post-treatment at 1300 ℃. Elevating the solution temperature to 1310 ℃ results in only a minor area of RX on the outer platform of the fourth stage in the DD5 SC test plate. The micro-shrinkage porosity and eutectic content of the as-cast and solution heat treated CMSX-4 alloy are both higher than those of the DD5 alloy. The higher content of eutectic and micro-shrinkage porosity provides more nucleation sites and quantities for RX in the CMSX-4 alloy， while the solution heat treatment temperatures above the γ' phase dissolution temperature weakens the pinning effect of coarse γ' phase on RX growth， and high melting point carbides and residual eutectic become important factors hindering RX growth. In addition， the high content of Co element reduces the stacking fault energy of the CMSX-4 alloy， making it with a high recrystallization tendency.

For the forging of GH4169, there are often serious mixed and coarse grains that need to be uniformly refined through a multi-stage annealing process. However, it will need to take a lot of time and cost to explore suitable multi-stage annealing process parameters if we only employ the experimental method. The cellular automata (CA) simulation can reveal the evolution of microstructure during forming and annealing, which can obviously reduce the number of experiments. Therefore, in the study, a CA model to simulate the evolution of grain microstructure, dislocation density and delta phase is established. The results demonstrate that the established CA model can effectively predict the microstructural evolution of GH4169. The correlation coefficient exceeds 0.94. Furthermore, using the CA simulation, an optimized multi-stage annealing parameter of "1000 degrees Cx 3 min+ 1000 degrees C-5 min-950 degrees C+ 950 degrees Cx 50 min" has been identified, which is also verified by experiments. These findings further verify the accuracy and reliability of the model in simulating microstructural evolution during the annealing process of GH4169 forgings. Eventually, based on the CA simulation, the formation mechanism for the uneven grain growth in the annealed microstructure is revealed. At original deformed grain boundaries, dynamic recrystallization (DRX) grains grow slowly, whereas static recrystallization (SRX) grains at DRX boundaries or delta phase boundaries within original deformed grains grow rapidly.