20 August 2026, Volume 33 Issue 4

    

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EXPERT FORUM
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  Effects of ball-milling treatment on microstructure and electrochemical performance of La_0.6Y_0.4Ni_3.75Al_0.15Mn_0.2 alloy

  DENG Anqiang, TAN Zhouxun, YE Chengxin, CHANG Hao, TIAN Ye, MU Guofeng

  Metallic Functional Materials. 2026, 33(4): 1-12. https://doi.org/10.13228/j.boyuan.issn1005-8192.20260016

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  Annealed La_0.6Y_0.4Ni_3.75Al_0.15Mn_0.2 superlattice hydrogen storage alloys were prepared using a vacuum arc-melting furnace and a vacuum tube-type annealing furnace. The alloys were subsequently ball-milled for 1,3 and 6 h under inert atmosphere protection. The effects of ball-milling time on the surface structural characteristics and electrochemical properties of the hydrogen storage alloys were investigated. XRD results indicate that the untreated alloy consists of CaCu₅,Pr₅Co₁₉,and Ce₅Co₁₉ type multiphase structures. After ball-milling,the phase structure of the alloy remains unchanged.however,the diffraction peak intensities are significantly reduced and pronounced peak broadening is observed,suggesting the formation of amorphous and nanocrystalline structures. SEM and EDS analyses show that ball-milling markedly reduces the particle size,eliminates sharp edges,and results in nearly spherical particle morphology. Moreover,the elemental distribution remains uniform after ball milling,indicating that the process does not alter the elemental distribution. Particle size analysis reveals that the powder particle size decreases significantly after ball-milling,exhibiting a decrease-increase trend with prolonged milling time. As the ball-milling duration increases,the activation performance of the alloy electrodes is notably improved and the maximum discharge capacity as well as other electrochemical properties first increase and then decrease. When the ball-milling time is 3 h,the maximum discharge capacity increases from 318.5 mA·h/g(without ball-milling) to 339.4 mA·h/g, and the high-rate dischargeability HRD₁₂₀₀ increases from 77.6% to 80.5%.Ball-milling has a significant positive effect on enhancing the hydrogen storage performance of the alloy,and an appropriate ball-milling treatment can effectively optimize its microstructure and electrochemical properties.
RESEARCH AND TECHNOLOGY
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  Electrochemical performance of Prussian blue-silicon proton batteries in H₃PO₄ electrolyte

  LIU Jiaxin, LAN Xuan, FANG Miaomiao, ZHANG Haiming, MA Zhewen, LUO Yongchun

  Metallic Functional Materials. 2026, 33(4): 13-22. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250108

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  FeHCF,NiHCF and ZnHCF Prussian blues were synthesized by chemical co-precipitation method,and amorphous a-Si thin film materials were prepared by magnetron sputtering. The chemical performance of the proton batteries constructed by Prussian blue and a-Si electrodes in H₃PO₄ electrolyte was studied. The results show that the synthesized FeHCF and NiHCF have cubic crystal structure,while ZnHCF has hexagonal crystal structure. All three materials possess hierarchical pore structures comprising micropores and mesopores,with a pore size distribution range of 2-50 nm. NiHCF demonstrates good charge-discharge performance in 4 mol/L phosphoric acid solution, with a discharge capacity of 69 mA·h/g. FeHCF, ZnHCF and a-Si electrodes exhibit favorable charge-discharge performance in 8 mol/L H₃PO₄, with maximum discharge capacities of 26.5, 36.6 and 231.3 mA·h/g, respectively. For the constructed a-Si|H₃PO₄(4 mol/L)|NiHCF proton battery,under the condition of a charge and discharge current density of 100 mA/g,the maximum discharge capacity of the battery is 43.4 mA·h/g,and the capacity retention rate is about 49.6% after 200 charge and discharge cycles. At a discharge current density of 1 400 mA/g,the battery discharge capacity reaches 28 mA·h/g,still releasing 62.2% of the initial maximum capacity,showing good high-rate discharge performance. The above work provides certain references for the design and selection of new electrode materials and the optimization of electrolyte for proton batteries.
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  Effects of C and Ni on microstructure and properties of 20MnMoNb steel for deep-sea pressure equipment

  HE Xikou, WANG Yongjun, LIU Huasong, LIU Qicong

  Metallic Functional Materials. 2026, 33(4): 23-31. https://doi.org/10.13228/j.boyuan.issn1005-8192.20260142

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  Improving the hardenability of steels for ultra-heavy forgings is crucial for achieving uniform strength and toughness across the entire cross-section. Based on a simulation of the thermal history at the core of a 370 mm thick cylindrical shell forging, the effects of carbon and nickel enrichment on the microstructure and mechanical properties of a 20MnMoNb steel were systematically compared. The results show that although both C and Ni enhance hardenability, their underlying mechanisms of microstructural control are fundamentally different. After heat treatment, the C-enriched steel developed extensive regions characterized by low precipitate density and an absence of sub-grain boundaries. Its Charpy impact energy at 0 ℃ dropped sharply from 128.7 J after tempering at 640 ℃ to 62.3 J upon increasing the tempering temperature to 650 ℃, while its room-temperature tensile strength underwent accelerated softening in the higher tempering range. Analysis reveals that the morphological difference of martensite-austenite (M-A) constituents in the as-quenched microstructure causes temper carbides to precipitate preferentially within lath-like bainite regions. The resulting chemical potential gradient drives the directional migration of carbon from granular bainite regions toward lath-like bainite regions, which is the key mechanism responsible for the formation of the low-precipitate, sub-grain-free zones. Carbon enrichment intensifies this effect, leading to a more heterogeneous spatial distribution of carbides and a heightened sensitivity of strength and toughness to tempering temperature. In the Ni-enriched steel, a lower bainite transformation temperature promotes a more uniform as-quenched microstructure, narrowing the temporal disparity in M-A decomposition during tempering and thereby suppressing the carbon migration effect. Combined with the solid-solution toughening conferred by Ni, this results in stable strength-toughness synergy across the entire tempering temperature range, providing an effective alloy design strategy for ultra-heavy wall forgings.
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  Optimization of femtosecond laser drilling process for 18Ni(200D) alloy based on response surface methodology

  XU Quan, ZOU Renzhen, ZHAO Ruyi, CHEN Junming, TANG Haimin, WU Hongxing, LIU Guang

  Metallic Functional Materials. 2026, 33(4): 32-39. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250161

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  To address the challenges of machining micro-deep holes with high aspect ratios and stringent morphological accuracy for pressure measurement orifices in cryogenic wind tunnel models made of 18Ni(200D) alloy, this study employs a Box-Behnken design to systematically investigate the effects of femtosecond laser parameters—single-pulse energy (100-160 μJ), scanning speed (100-800 mm/s), and repetition frequency (10-100 kHz)—on through-hole quality. Predictive models for the diameter deviation (η), average wall taper angle (α), and outlet ellipticity (ε) were established using Box-Cox transformation and second-order regression analysis. Residual diagnostics confirmed that the models satisfy the assumptions of normality, homoscedasticity, and independence. The results indicate that η is significantly influenced by the linear and quadratic effects of energy and scanning speed; α is primarily governed by the quadratic effects of scanning speed and repetition frequency; and ε exhibits highly significant linear and quadratic dependencies on all three factors. Response surface optimization revealed that optimal machining quality (η<3%,α≈9°,ε≈1.2) is achieved at approximately 130 μJ, 450 mm/s, and 50 kHz. This study defines an engineering-viable process window via the response surface methodology, enabling high-precision and repeatable micro-hole drilling on high-strength 18Ni(200D) alloy, thereby providing critical guidance for the precision manufacturing of pressure measurement orifices for cryogenic wind tunnel models.
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  Microstructure and tensile properties of Ti-46Al-4Nb-0.5Mo-0.08B alloy fabricated by two-step extrusion

  WANG Hongwei, LIU Wenlong, GUO Dongwei, LIANG Xiaobo, LIANG Yongfeng, ZHANG Ji

  Metallic Functional Materials. 2026, 33(4): 40-48. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250157

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  Square bars of a Ti-46Al-4Nb-0.5Mo-0.08B alloy with fine grains and a homogeneous microstructure were successfully fabricated via two-step canned extrusion with a large accumulative extrusion ratio, providing high-quality preforms for subsequent forging of TiAl alloy blades. The microstructural evolution of the bars during the two-step extrusion process was systematically investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results indicate that after the first extrusion, a considerable number of residual lamellar structures remained in the bar, with a noticeable difference between the center and edge regions. Following the second extrusion, the original coarse lamellae were essentially eliminated, and complete dynamic recrystallization occurred, resulting in a uniform near-γ microstructure. Only a minimal amount of B2 phase precipitated at the grain boundaries during cooling after extrusion. The obtained bars exhibited a room-temperature yield strength of 705 MPa with an elongation of 3.32%, and a yield strength of 474 MPa with an elongation of 32.75% at 760 ℃. The fine grain size and the minimal B2 phase content contribute to the favorable room-temperature ductility of the bars.
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  Influence of Cr and V addition on the impact wear resistance of iron-based hardfacing alloys

  SI Shanshan, JIANG Yuanbo, LI Binzhou, YANG Yu, ZHANG Dayue, WANG Yijia

  Metallic Functional Materials. 2026, 33(4): 49-55. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250180

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  Hardfacing alloys serve as one of the effective ways to enhance the impact wear resistance of high-manganese cast steel.Vanadium addition in existing iron-based hardfacing alloys is relatively low. In this work, several Fe-Cr-C-V hardfacing alloys with high V content were designed to investigate the effects of Cr and V contents on the amount and distribution of hard phases M₇C₃ and VC,as well as their influence on impact wear resistance. In this study, five Fe-Cr-C-V hardfacing alloys with different Cr and V contents were fabricated using plasma surfacing. The microstructure of the hardfacing alloys was characterized using optical metallographic microscope, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy(EDX). The fraction of carbides in the alloy system was calculated using JMatPro software, and the impact wear resistance of hardfacing alloys was evaluated through hardness testing and impact wear experiments. The primary strengthening phases in hardfacing alloys were (Fe,Cr)₇C₃ and VC carbides. VC exhibited a spherical morphology with a size of 2-5 μm, exhibiting a fine and dispersive distribution. (Fe,Cr)₇C₃ exhibits a dendritic morphology and interlocks with one another to form a network structure. Carbide content was calculated by JMatPro software, indicating that the predominant carbides were MC and M₇C₃, resulting in optimal impact abrasive wear resistance when the V content ranged from 14.0% to 15.0%. When the V content was 15.0%, the hardness of the hardfacing layer reached 58.4HRC, and the mass loss was minimised under an impact energy of 5 J. The impact wear morphology was characterised by shallow ploughing grooves, minor spalling pits, and a small amount of embedded fine particles.
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  Analysis of influence of laser cleaning effect on identification of surface oxide layer damage on stainless steel parts

  QIAO Shuo, LU Ying, HAN Bingzheng, SHEN Ruili, LI Ximin

  Metallic Functional Materials. 2026, 33(4): 56-62. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250111

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  The damage to the oxide layer caused by laser cleaning is visually very subtle compared with the unda-maged oxide layer,and the contrast between the damaged area and the background is low, making it difficult to distinguish clearly in the original image,resulting in a decrease in the accuracy of damage recognition. A new method was proposed to solve this problem, and the influence of laser cleaning effect on the identification of surface oxide layer damage on stainless steel parts was analyzed. The Otsu algorithm was used to automatically calculate the optimal global threshold,determine the image of the damaged area of the oxide layer on the surface of stainless steel parts,preliminarily divide the image into oxide layer and non-oxide layer,and separate the oxide layer from the overall image. The watershed algorithm was employed to address the boundary ambiguity issue in the initial Otsu segmentation,enabling precise segmentation of oxide layer regions that are in contact or overlap with each other,while eliminating interference from non-target areas. Differential operation was performed between the original image of the oxide layer on the surface of stainless steel parts and the image after nonlinear diffusion. Based on the standard deviation of image blocks in the differential image,an adaptive binarization model was constructed to perform binarization processing on the differential image. While preserving important edge information, background non-uniformity was suppressed,thereby achieving damage identification of the oxide layer on the surface of stainless steel parts and effectively improving the recognition performance. Experimental results demonstrate that the proposed method can accurately identify surface oxide layer damage on stainless steel parts.
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  Microstructure and properties analysis of Q345 grade low-temperature resistant hot-rolled H-section steel in the Nb-Ti system

  WU Meizhuang, CHEN Hui, XIA Meng, SHEN Qiancheng, WANG Jie, XING Jun

  Metallic Functional Materials. 2026, 33(4): 63-71. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250034

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  To study the microstructure and properties of Q345 grade bridge hot-rolled H-section steel in the Nb-Ti system,two alloy composition designs, namely high niobium with low titanium and high titanium with low niobium, were adopted for experimental trials. The experimental results show that the mechanical properties of the tested steels from both the high niobium and low titanium alloy system and the high titanium and low niobium alloy system meet the requirements of the Q345q steel grade(yield strength not less than 345 MPa) D and E level(impact energy no less than 120 J at -20 and -40 ℃). Among them,the high titanium and low niobium composition has excellent strength indicators,but the impact toughness is slightly lower. Through microstructure analysis,the microstructure of the high niobium and low titanium composition is mainly ferrite+pearlite in the room temperature,while that of the high titanium and low niobium composition is mainly bainite+ferrite+minor pearlite. By using SEM scanning electron microscopy for observation,it was found that the C atom content in the pearlite region of the high-niobium and low-titanium composition test steel was slightly higher than that in the ferrite region. However,for test steel B with high titanium and low niobium,the C atom content in the pearlite region was not significantly different from that in the ferrite region. This indicates that a metastable phase transformation occurred in the microstructure of test steel B,eventually forming a bainite structure enriched with carbides, thereby enhancing the strength of the product.
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  Micro-mechanism of microstructure evolution of new low-alloy high-strength steel during heat treatment

  LI Yingqun

  Metallic Functional Materials. 2026, 33(4): 72-79. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250186

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  Q355E novel low-alloy high-strength steel is taken as the research object to investigate the microscale mechanism of microstructure evolution of low-alloy high-strength steel during heat treatment. Scanning electron microscope (SEM),transmission electron microscope(TEM), and X-ray diffraction(XRD) are employed to characterize the microstructural morphology and evolution of the tested steel before and after lanthanum treatment via the addition of La-Fe master alloy under different heat treatment process parameters. The experimental results show that the solution temperature exerts a significant effect on the austenite grain size and martensite lath size, and the optimal solution temperature range is determined to be 800-900 ℃. In the tempering process, the austenite content remains stable with increased carbon content at 300-320 ℃, while the austenite content decreases when the tempering temperature exceeds 320 ℃, confirming 320 ℃ as the optimal tempering temperature. Cryogenic treatment at -40 ℃ achieves the optimal matching state of austenite content and carbon content. Moreover, the addition of La-Fe master alloy promotes the transformation of internal inclusions into spherical rare-earth composite oxysulfides, which effectively improves the comprehensive properties of the steel material.
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  Mechanisms of laser cleaning of steel surfaces in oxygen environment and its corrosion resistance

  DUAN Jiazhen, SHI Ruxin, ZHANG Wei, WANG Qing, REN Xianming

  Metallic Functional Materials. 2026, 33(4): 80-93. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250104

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  Although traditional chemical blackening process is widely used for corrosion protection on metal surfaces, it poses environmental pollution issues. A novel technique was proposed for in-situ formation of a continuous black Fe₃O₄ oxide film on steel surfaces using nanosecond pulse laser irradiation in an oxygen environment, and the relationship between film quality and laser parameters was evaluated. The research indicates that the thickness of the oxide film on steel surfaces increases with the increase in laser energy density and scan times but decreases with the increase in scanning speed, with the film thickness adjustable within the range of 1 to 12 μm. Despite the presence of mud cracks in the laser-blackened film, this defect does not significantly reduce the corrosion resistance and adhesion strength to the substrate. Electrochemical test results demonstrate a significant enhancement in corrosion resistance of steel with laser cleaning in oxygen environment, comparable to traditional chemical blackening. Salt spray tests further confirm that a film thickness in the range of 4.4 to 7.5 μm provides optimal corrosion resistance. Moreover, point defects in the oxide layer are identified as crucial factors affecting corrosion resistance. Therefore, precise control of laser processing parameters is crucial to ensure the quality and corrosion resistance of the oxide film. The findings of this study provide important guidance for optimizing future laser processes, showcasing the potential of laser technology in preparing high-performance anti-corrosion surface coatings.
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  Dielectric properties and aging behavior of polyimide/ZnO nanocomposite materials

  XU Hanbin, LIAO Jiansheng, LIN Shaowei, LIN Youdong

  Metallic Functional Materials. 2026, 33(4): 94-98. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250105

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  Polyimide/zinc oxide nanocomposites were systematically investigated for their dielectric properties and aging behavior in distribution network insulation applications. Polyimide samples with varying zinc oxide mass fractions were prepared via the solution casting method, including pure polyimide (PA0) and nanocomposites with 1% (PA1), 3% (PA3), 5% (PA5), and 7% (PA7) zinc oxide additions. Accelerated aging was conducted by applying 200 h of ultraviolet irradiation and direct current electrical stress to the samples using a customized aging chamber, and the sample performance evolution was monitored in real time. Surface morphology was observed by scanning electron microscopy, phase structure was analyzed by X-ray diffraction spectroscopy, and dielectric properties were evaluated through measurements of relative permittivity and direct current resistivity. The results indicate that the samples with 1% and 3% zinc oxide additions (PA1 and PA3) exhibit superior electrical stability during aging, characterized by smaller fluctuations in relative permittivity and higher direct current resistivity. Moderate zinc oxide addition significantly enhances the dielectric properties and aging resistance of polyimide nanocomposites. These findings provide a reference for the development of insulation materials for distribution networks and are of positive significance for improving power transmission reliability.
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  Analysis of antimicrobial properties of low-carbon copper-containing steel surface

  WU Jiansheng, LIU Jingjia, LIN Hongchun, HU Mingzhu, WU Yanxin, JIANG Haitao

  Metallic Functional Materials. 2026, 33(4): 99-104. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250128

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  Copper (Cu) is widely used in household appliances, medical treatment, catering and other industries worldwide. Besides excellent electrical and thermal conductivity, Cu is well recognized for its outstanding antimicrobial property. Among antimicrobial metals, Cu features easy availability and low cost. Accordingly, copper-containing steels can achieve superior antimicrobial performance after antimicrobial heat treatment. Taking the surface antimicrobial property difference between low-carbon copper-containing steel and ordinary low-carbon steel as the research object, the effects of annealing temperature and Cu content on the antimicrobial performance of low-carbon copper-containing steel were investigated by optical microscopy (OM), ion dissolution test and antimicrobial experiment. The results show that within a certain range, higher Cu content leads to more precipitated Cu particles, higher dissolved Cu ion concentration and better antimicrobial effect. After co-cultivation with Escherichia coli for 24 h, the low-carbon copper-containing steel achieves a 100% sterilization rate against Escherichia coli, which presents favorable application potential in food and medical material fields.
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  Thermal management analysis of UPS lead-acid batteries by coupling heat pipes with phase change materials

  LI Le, ZHANG Yan, LIU Yong

  Metallic Functional Materials. 2026, 33(4): 105-109. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250101

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  The performance of lead-acid batteries is significantly affected by temperature. In uninterruptible power supply(UPS) systems,lead-acid batteries are key energy storage components. Excessively high temperatures can accelerate the chemical reaction rate inside the battery,which may lead to overcharging or overdischarging of the battery,thereby affecting its capacity and lifespan. Given this,a well-performing thermal management system(TMS) is indispensable. Its core function is to promptly and effectively dissipate the heat generated by lead-acid batteries under high-load cycling conditions. A hybrid thermal management system(HTMS)that combines phase change materials(PCM)with six flat heat pipes. Under the condition of continuous discharge at a high current of 150 A for 1 400 s without interruption,this system can precisely control the temperature within 40 ℃. During the experiment,two K-type thermocouples(marked as T1 and T2 respectively)were arranged to achieve real-time monitoring of temperature changes. The entire research work covers three typical cases,namely the temperature distribution of batteries under natural convection,the temperature distribution when using heat pipe TMS,and the temperature distribution when using HTMS. The experimental results show that the HTMS system performs exceptionally well in cooling. Compared with the natural convection situation,HTMS can significantly reduce the temperature at T1 by 35%. Under the same comparison conditions,the heat pipe TMS can only reduce the temperature at T1 by 15%.
APPLICATION RESEARCH
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  Automatic identification of defects in live working hard hardware based on G-SAD2Det and X flaw detection technology

  CHEN Yizhong, ZHAO Weiyan, CHEN Kang, PANG Feng, CUI Ao, YANG Yunlü

  Metallic Functional Materials. 2026, 33(4): 110-116. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250112

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  Due to the small size of small hardware target,it is difficult to obtain the vertical/horizontal deformation maps of target details, which easily leads to misidentification. To address this issue, this study proposed an automatic defect identification method for live working hard hardware based on G-SAD2Dec and X-ray flaw detection technology. Based on the attenuation degree of X-rays passing through materials, high-resolution internal structural images of hard hardware were obtained through X-ray flaw detection technology. G-SAD2Det captures the subtle vertical/horizontal deformation characteristics of small hardware targets in images by introducing a global attention mechanism and multi-scale vertical/horizontal deformation fusion, learns the target box offset through an independent deep learning method to optimize the target box position, and realizes automatic identification of hardware defects. The experimental results show that the method identifies bolt loosening defects in the horizontal range of 0-4 cm and vertical range of 4-6 cm,nut missing defects in the horizontal range of 2-8 cm and vertical range of 7-9 cm, pin missing defects in the horizontal range of 5-8 cm and vertical range of 5-7 cm, pin loosening defects in the horizontal range of 3-8 cm and vertical range of 5-7 cm, and has accurate identification effect.
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  Effect and optimization of laser heat treatment parameters on the hardness and wear resistance of YG8 cemented carbide tools

  ZHANG Hua, LI Xiaoyan, SHAO Changkun, YAO Haibin, JIN Mingxiao

  Metallic Functional Materials. 2026, 33(4): 117-125. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250150

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  This study systematically investigated the effects of laser heat treatment parameters, including laser power, scanning speed, and processing temperature, on the hardness and wear resistance of YG8 cemented carbide tools. The laser power was set at 640, 840, and 1 040 W, scanning speeds of 1.0, 1.5, 2.0, and 2.5 mm/s, and processing temperatures of 600, 800, and 1 000 ℃. A hardness tester and a wear testing machine were employed to identify the optimal process combination and elucidate the underlying mechanism. The results indicated that the highest surface hardness under a Q4.9 N load was (150HV±4HV) with the lowest steady-state coefficient of friction of (0.292±0.015) at a laser power of 840 W, (160HV±4HV) with coefficient of friction of (0.350±0.015) at a scanning speed of 2.0 mm/s, and (152HV±4HV) with coefficient of friction of (0.30±0.015) at a processing temperature of 800 ℃, respectively. The optimal combination of laser power at 840 W, scanning speed of 2.0 mm/s, and processing temperature of 800 ℃ yielded the best overall hardness and wear resistance for the YG8 tools. The findings demonstrate that rational control of laser heat treatment parameters can significantly improve the surface performance of YG8 cemented carbide tools, making them particularly suitable for high-precision machining applications.
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  GER-YOLO detection of crack defect in laser additive manufacturing of high-performance metal components

  YANG Shuai, HU Yanling, HU Yanbin, GUO Peihong, WANG Zhuoran, DU Mengkai

  Metallic Functional Materials. 2026, 33(4): 126-133. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250117

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  The high-performance metal components manufactured by laser additive manufacturing have complex structures and surface conditions such as uneven roughness, oxide layer, and unfused particles, which cause scattering of detection signals, reduce the signal-to-noise ratio of crack reflection signals, mask small cracks,and affect the accuracy of detection results. Therefore, a GER-YOLO detection method for crack defects in high-performance metal components manufactured by laser additive manufacturing is proposed. By using digital sampling technology, combined with the defect development trends of different metal materials and the surface roughness of components, a discretization model of the surface roughness of metal components is established. Using the established model, the signal emission state is simulated to obtain the scattering law of detection signals, and the GER-YOLO network prediction head structure is constructed to extract the defect signals characteristics of metal components. X-rays are used to obtain detection signals, and the recognition effect of defect images is improved through contrast enhancement technology. The GER-YOLO detection model is optimized by introducing the coverage ratio threshold and Distribution Focal Loss function. The obtained model is used to analyze defect images and annotate crack defect characteristics. Finally, based on the annotated characteristics, an edge detection algorithm is used to obtain small defect image blocks, binarization and Canny operators are used to obtain the defect size, and the pulse reflection method is combined to determine the defect position, realizing the crack defect detection of additive manufacturing metal components. Experimental results conducted using the aforementioned design method demonstrated that it achieves a detection accuracy of over 70% for various crack defects, enabling precise identification of cracks in additive manufacturing metal components.
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  Performance analysis of carbon-based metal-supported catalysts for heavy metal treatment from wastewater

  PENG Dianqin, ZHU Menglong

  Metallic Functional Materials. 2026, 33(4): 134-139. https://doi.org/10.13228/j.boyuan.issn1005-8192.20250125

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  Wastewater has complex components containing numerous impurities and toxic substances, so catalysts are prone to contamination and poisoning during long-term operation, resulting in decreased activity. Carbon-based metal-supported catalysts integrate metal catalysts with carbon-based carriers and can be used to treat heavy metals in wastewater. To explore the performance of such catalysts in heavy metal treatment of wastewater, four types of carbon-based metal-supported catalysts (Fe-NCNTs-700, Fe-NCNTs-800, Co-NCNTs-700, Co-NCNTs-800) were prepared with cobalt (Co) and iron (Fe) at 700 and 800 ℃ respectively, based on electro-Fenton theory. Experimental results show that at the same temperature, materials prepared with metallic cobalt have stronger H₂O₂ generation capacity than those prepared with metallic iron; Co-NCNTs materials have smoother surfaces than Fe-NCNTs materials with observable carbon nanotube structures, and Fe-NCNTs-800 presents flaky structures on the surface at 800 ℃, which is identified as Fe(OH)₃(iron hydroxide) via XRD analysis. In wastewater heavy metal treatment experiments, Fe-NCNTs-800 exhibits equivalent treatment capacity for common wastewater heavy metals to Co-NCNTs-800, because Fe(OH)₃in it can generate more hydroxyl radicals to react with heavy metals and reduce heavy metal content in wastewater. In cyclic continuous experiments, Fe-NCNTs-800 shows slightly lower recycling efficiency, but comprehensively considering the cost and dosage of cobalt, and balancing the treatment effect and cost, Fe-NCNTs-800 carbon-based metal-supported catalyst has better practical application prospects.