Journal of Materials Research and Technology-Jmr&t最新文献_第10页

Multiscale stabilization mechanisms of β″ precipitates in Al–Mg–Si alloys: Mg5Al2Si4 dominance through thermodynamic-mechanical-interfacial synergy Al-Mg-Si合金中β″沉淀的多尺度稳定机制：Mg5Al2Si4通过热力学-力学-界面协同作用的优势

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-12 DOI: 10.1016/j.jmrt.2025.09.030

Hong Mao , Jingwen Pan , Zhuoliang Yu , Jiaming Liu , Zhuowei Xiao , Yuman Zhu , Yinxing Hu , Xiaohong Zhang , Yong Du

{"title":"Multiscale stabilization mechanisms of β″ precipitates in Al–Mg–Si alloys: Mg5Al2Si4 dominance through thermodynamic-mechanical-interfacial synergy","authors":"Hong Mao , Jingwen Pan , Zhuoliang Yu , Jiaming Liu , Zhuowei Xiao , Yuman Zhu , Yinxing Hu , Xiaohong Zhang , Yong Du","doi":"10.1016/j.jmrt.2025.09.030","DOIUrl":"10.1016/j.jmrt.2025.09.030","url":null,"abstract":"<div><div>Investigating the intrinsic characteristics of Al-containing precipitates in age-hardenable aluminum alloys and exploring their synergistic interactions with dislocations, interfaces, and the aluminum matrix represents a cutting-edge strategy for designing lightweight, high-strength aluminum alloys. This study elucidates the stability competition mechanisms among β″ precipitates (Mg<sub>5</sub>Si<sub>6</sub>, Mg<sub>5</sub>Al<sub>2</sub>S<sub>i4</sub>, and Mg<sub>4</sub>Al<sub>3</sub>Si<sub>4</sub>) in Al–Mg–Si alloys through multiscale computational analyses. First-principles calculations reveal that Mg<sub>5</sub>Al<sub>2</sub>Si<sub>4</sub> exhibits superior thermodynamic stability, as evidenced by its minimized formation enthalpy and negative cohesive energy, which govern spontaneous nucleation and coarsening resistance. Furthermore, Mg<sub>5</sub>Al<sub>2</sub>Si<sub>4</sub> demonstrates optimal mechanical properties, including shear modulus, Young's modulus, and Pugh ratio, synergistically enabling enhanced dislocation pinning capability and balanced strength-ductility synergy. Notably, interfacial analysis indicates that Mg<sub>5</sub>Al<sub>2</sub>Si<sub>4</sub> effectively suppresses interfacial decohesion by stabilizing semi-coherent interfaces through the lowest interfacial energy and highest adhesion work among the studied phases. In contrast, Mg<sub>5</sub>Si<sub>6</sub> exhibits inferior stability, functioning merely as a transient metastable precursor during aging. These findings establish Mg<sub>5</sub>Al<sub>2</sub>Si<sub>4</sub> as the dominant strengthening phase in peak-aged conditions. By constructing a multiscale correlation framework integrating thermodynamic, mechanical, and interfacial properties, this work provides a universal paradigm for the design of precipitation-strengthened aluminum alloys.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 145-153"},"PeriodicalIF":6.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advantages of in-situ impregnation 3D printing in continuous flax/PLA biocomposites for optimized mechanical properties in structural applications 原位浸渍3D打印连续亚麻/PLA生物复合材料在结构应用中优化机械性能的优势

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-12 DOI: 10.1016/j.jmrt.2025.09.042

Hani Mehaba , Lotfi Toubal , Zouheyr Belouadah

{"title":"Advantages of in-situ impregnation 3D printing in continuous flax/PLA biocomposites for optimized mechanical properties in structural applications","authors":"Hani Mehaba , Lotfi Toubal , Zouheyr Belouadah","doi":"10.1016/j.jmrt.2025.09.042","DOIUrl":"10.1016/j.jmrt.2025.09.042","url":null,"abstract":"<div><div>The in-situ impregnation 3D printing technique offers a unique advantage over traditional composite manufacturing methods: the ability to control fiber weight fraction within a single print. This study demonstrates this capability through the printing of continuous flax fiber-reinforced PLA biocomposites. A parametric study was conducted to determine the optimal printing parameters, including nozzle temperature and cooling fan usage. Subsequently, samples with four different fiber weight fractions (0, 30, 40, and 50 wt%) were printed using the optimized parameters. Tensile properties were evaluated through both tensile testing and acoustic impulse measurements, while Shore D hardness, density and porosity were also assessed. The results reveal a significant improvement in tensile properties and an increase in density with increasing fiber weight fraction, accompanied by a decrease in Shore D hardness. Additionally, the choice of printing pattern, influences the tensile properties and damage mechanisms. These findings highlight the potential of in situ impregnation for producing custom fiber-reinforced biocomposites with tailored mechanical properties at a low cost.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 355-367"},"PeriodicalIF":6.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effect of heat treatment on microstructure and mechanical properties of Ti3Zr1.5NbVAl0.25 refractory high entropy alloys fabricated by directed energy deposition 热处理对定向能沉积Ti3Zr1.5NbVAl0.25难熔高熵合金组织和力学性能的影响

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-12 DOI: 10.1016/j.jmrt.2025.09.097

Bang Xiao , Yan Li , Songtao Li , Aimin Wang , Huameng Fu , Haifeng Zhang , Zhengwang Zhu

{"title":"The effect of heat treatment on microstructure and mechanical properties of Ti3Zr1.5NbVAl0.25 refractory high entropy alloys fabricated by directed energy deposition","authors":"Bang Xiao , Yan Li , Songtao Li , Aimin Wang , Huameng Fu , Haifeng Zhang , Zhengwang Zhu","doi":"10.1016/j.jmrt.2025.09.097","DOIUrl":"10.1016/j.jmrt.2025.09.097","url":null,"abstract":"<div><div>Directed energy deposition (DED) is recognized as an advanced technology for fabricating refractory high entropy alloys (RHEAs), and appropriate heat treatment of DED materials may further enhance their properties. In this work, Ti<sub>3</sub>Zr<sub>1.5</sub>NbVAl<sub>0.25</sub> RHEAs were prepared using DED, and the effects of annealing (550 °C/5 h) and solid solution (800 °C, 1000 °C, and 1200 °C/30 min) treatment on the microstructure and mechanical properties of the RHEAs were systematically investigated. The results indicate that needle-like C14 Laves phases precipitated in the matrix after annealing, which significantly degraded the plasticity. Following solid solution treatment at temperatures above 800 °C, the C14 Laves phase dissolved, resulting in a single phase BCC structure in the matrix. As the solid solution temperature increased from 800 °C to 1200 °C, abnormal grain growth occurred, with the average grain size expanding from 30.2 μm to 292.0 μm. The solid solution treatment had a negligible impact on strength and microhardness, while it reduced plasticity but enhanced impact toughness. The 1000 °C solid solution samples demonstrated the most balanced mechanical properties, with a yield strength of 871 MPa and a fracture elongation of 24.7 %, showing minimal deviation from the DEDed samples. Importantly, the impact toughness reached 55.0 J/cm<sup>2</sup>, representing a remarkable increase of 201 % compared to the DEDed samples. This study provides valuable insights for the development of RHEAs that achieve an optimal combination of strength and toughness.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 94-107"},"PeriodicalIF":6.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synergistic strengthening driven by boundary-dislocation architectures in hot-rolled NiV7 alloy 热轧NiV7合金边界位错组织驱动的协同强化

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-12 DOI: 10.1016/j.jmrt.2025.09.095

Linqing Yang , Hongyan Wang , Shiqi Li , Xiaoyi Pu , Jiaxin Yu , Han Xiao , Ming Wen

{"title":"Synergistic strengthening driven by boundary-dislocation architectures in hot-rolled NiV7 alloy","authors":"Linqing Yang , Hongyan Wang , Shiqi Li , Xiaoyi Pu , Jiaxin Yu , Han Xiao , Ming Wen","doi":"10.1016/j.jmrt.2025.09.095","DOIUrl":"10.1016/j.jmrt.2025.09.095","url":null,"abstract":"<div><div>Single-phase NiV7 alloy plates were hot-rolled at 900 °C, 1050 °C and 1200 °C, respectively. Electron-backscatter diffraction (EBSD) analyses reveal that elevating the rolling temperature enlarges the average grain size from 18.2 μm to 32.5 μm and promotes the development of strong crystallographic texture as well as abundant annealing twins. The geometrically necessary dislocation (GND) density decreases from 1.16 × 10<sup>15</sup> m<sup>−2</sup> at 900 °C to 0.82 × 10<sup>15</sup> m<sup>−2</sup> at 1200 °C, and the substructure increased from 40.5 % to 77.2 %, indicating a significant dynamic recovery. Consistent with these microstructural changes, the ultimate tensile strength drops from 796.9 MPa to 575.1 MPa, whereas total elongation increases from 21 % to 30 %. Quantitative assessment of Hall-Petch, twin-boundary and dislocation-strengthening contributions demonstrates that an optimal strength-ductility synergy can be attained by adjusting the hot-rolling temperature to balance grain size, twin density and dislocation content. This study provides important guidance for the design and fabrication of high-performance nickel-vanadium sputtering targets for advanced thin film applications.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 124-133"},"PeriodicalIF":6.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of precipitates on recrystallization of Al–Mg–Si alloy during hot deformation and sub-grain rotation behavior in dynamic recrystallization 析出相对Al-Mg-Si合金热变形再结晶及动态再结晶亚晶粒旋转行为的影响

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-12 DOI: 10.1016/j.jmrt.2025.09.094

Peng Sun , Rensong Huang , Li Wan , Shanju Zheng , Yonghua Duan , Mengnie Li

{"title":"Effects of precipitates on recrystallization of Al–Mg–Si alloy during hot deformation and sub-grain rotation behavior in dynamic recrystallization","authors":"Peng Sun , Rensong Huang , Li Wan , Shanju Zheng , Yonghua Duan , Mengnie Li","doi":"10.1016/j.jmrt.2025.09.094","DOIUrl":"10.1016/j.jmrt.2025.09.094","url":null,"abstract":"<div><div>Dynamic recrystallization (DRX) is one of the most significant microstructural features during thermal deformation. However, systematic studies on the microstructural evolution during its nucleation remain insufficient. In this work, the influence of Mg<sub>2</sub>Si precipitates on recrystallization in Al–Mg–Si alloy during hot deformation was investigated, and the sub-grain rotation behaviors associated with different DRX nucleation mechanisms were further characterized. Results show that Mg<sub>2</sub>Si formed under deformation conditions of 450 °C/0.001 s<sup>−1</sup> promotes recrystallization. Continuous DRX (CDRX) grains originating within grain interiors and at grain boundaries exhibit opposite lattice rotation directions, whereas geometric DRX (GDRX) grains display random rotation orientations. Discontinuous DRX (DDRX) occurs without lattice rotation, being governed primarily by grain boundary migration. Notably, CDRX nucleation requires a greater sub-grain rotation angle than GDRX. This work presents the first detailed examination of the effects of cubic Mg<sub>2</sub>Si precipitates on recrystallization and provides a systematic characterization of sub-grain rotation behaviors in CDRX and GDRX, offering new insights into the thermal deformation mechanisms of Al–Mg–Si alloys.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 597-613"},"PeriodicalIF":6.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Revealing the influence of niobium addition on interphase precipitation in titanium microalloyed high-strength low alloy steel 揭示了添加铌对钛微合金化高强度低合金钢相析出的影响

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-12 DOI: 10.1016/j.jmrt.2025.09.088

Chunlei Shang , Gang Liu , Hong-Hui Wu , Haolin Ma , Feiyang Wang , Shuize Wang , Junheng Gao , Haitao Zhao , Chaolei Zhang , Xinping Mao

{"title":"Revealing the influence of niobium addition on interphase precipitation in titanium microalloyed high-strength low alloy steel","authors":"Chunlei Shang , Gang Liu , Hong-Hui Wu , Haolin Ma , Feiyang Wang , Shuize Wang , Junheng Gao , Haitao Zhao , Chaolei Zhang , Xinping Mao","doi":"10.1016/j.jmrt.2025.09.088","DOIUrl":"10.1016/j.jmrt.2025.09.088","url":null,"abstract":"<div><div>High-strength low-alloy (HSLA) steel is widely utilized in structural applications due to its excellent mechanical properties and formability. In this work, the influence of niobium on the precipitation behavior of HSLA steel is studied, and two distinct precipitation modes—dispersed and interphase precipitation—are identified within the ferritic matrix. A comparative analysis of their composition, morphology, and crystallographic orientation is conducted using advanced techniques, including scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), high-resolution transmission electron microscopy (HRTEM), and atom probe tomography (APT). The results show that interphase precipitates primarily consist of (Ti,Nb)C, whereas dispersed precipitates are identified as TiC. Nb is observed to significantly retard phase boundary migration and resulting in refined precipitate size. Despite differences in their precipitation mechanisms, both precipitation modes maintain a consistent crystallographic orientation relationship with the ferrite matrix. These findings enhance the fundamental understanding of Nb-driven precipitation in HSLA steels and offer insights for tailoring microstructure through alloying strategies.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 87-93"},"PeriodicalIF":6.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lowest sinterable temperature Ag nanoporous sheet bonding at 145–175 °C on Ag-plated Cu and interfacial microstructural degradation under 250 °C aging: Correlation with strength and fracture energy 145 ~ 175℃下银纳米孔片在镀银Cu上的最低烧结温度及250℃时效下界面微观结构的退化：与强度和断裂能的相关性

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-11 DOI: 10.1016/j.jmrt.2025.09.085

YehRi Kim , Seungjun Noh , Byeong Kwon Ju , Dongjin Kim

{"title":"Lowest sinterable temperature Ag nanoporous sheet bonding at 145–175 °C on Ag-plated Cu and interfacial microstructural degradation under 250 °C aging: Correlation with strength and fracture energy","authors":"YehRi Kim , Seungjun Noh , Byeong Kwon Ju , Dongjin Kim","doi":"10.1016/j.jmrt.2025.09.085","DOIUrl":"10.1016/j.jmrt.2025.09.085","url":null,"abstract":"<div><div>This study investigates the microstructural evolution and mechanical reliability of silver (Ag) nano-porous sintered joints bonded at low temperatures (145–175 °C) onto Ag-plated copper (Cu) substrates. We focus on their interfacial degradation behavior during thermal aging at 250 °C. Despite the exceptionally low bonding temperature, strong initial bonding was achieved, and thermal exposure for up to 250 h enhanced sinter neck growth and interfacial connectivity, resulting in increased shear strength and fracture energy absorption. However, extended aging beyond 500 h led to the formation of interfacial Cu<sub>x</sub>O layers and Kirkendall voids at the Cu/Cu<sub>x</sub>O interface, causing bond line thickness transition with delamination and a critical decline in mechanical performance. Microstructural and crystallographic analyses using SEM, EBSD, and XRD revealed stagnation of grain coarsening, texture development, and recrystallization behavior in both the sintered Ag and Ag plating layers. The failure mode transitioned from cohesive fracture within the Ag layer to interfacial separation at the oxidized Cu interface. These findings demonstrate that low-temperature Ag nanoporous sheet bonding can initially deliver robust interfacial strength, but long-term reliability at elevated temperatures is limited by diffusion-driven oxidation and void formation at the Cu interface.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 154-178"},"PeriodicalIF":6.6,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of cooling rate on the solidification behavior and elemental segregation in a cast NiCoCr-based superalloy 冷却速率对铸造镍铬基高温合金凝固行为和元素偏析的影响

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-11 DOI: 10.1016/j.jmrt.2025.09.071

Zhengye Zhang , Yunwei Pan , Zhongfeng Chen , Anping Dong

{"title":"Effect of cooling rate on the solidification behavior and elemental segregation in a cast NiCoCr-based superalloy","authors":"Zhengye Zhang , Yunwei Pan , Zhongfeng Chen , Anping Dong","doi":"10.1016/j.jmrt.2025.09.071","DOIUrl":"10.1016/j.jmrt.2025.09.071","url":null,"abstract":"<div><div>Understanding solidification behavior and elemental segregation in Ni-based superalloys is crucial for predicting the microstructural evolution in complex-structured castings, optimizing heat-treatment protocols, and enhancing product quality. In this work, a systematic study is conducted to elucidate the influence of cooling rate on the solidification microstructure and elemental segregation behavior in a newly NiCoCr-based superalloy, K439B. Differential scanning calorimetry and Thermo-Calc calculations are employed to obtain the alloy's liquidus (1349 ± 3 °C), solidus (1277 ± 1 °C), and primary solidification sequence (γ → γ + MC → γ + MC + η). In-situ high-temperature confocal scanning laser microscopy observations reveal a decrease in nucleation temperature (1316.7–1304.3 °C) and a Boltzmann-type evolution of solid fraction at different cooling rates. The segregation coefficients for Ti, Nb, and Ta exhibit strong positive segregation, while Ni, Co, and Cr show negative segregation. Dendrite morphology analysis shows that the secondary dendrite arm spacing (λ<sub>2</sub>) refines from 44.4 μm to 19.4 μm as the cooling rate increases. Precipitate analyses demonstrate that the γ′ phase refines from blocky (74 nm) to spherical (11 nm) with nearly constant volume fraction (15 %), and MC carbides evolve from equiaxed to rods (aspect ratio from 1.35 to 13.9) with a “rise-then-fall” in volume fraction (1.31 → 1.78 →1.57 %). In addition, a Ti-rich η-Ni<sub>3</sub>Ti phase precipitates in the interdendritic regions at a cooling rate of 200 °C·min<sup>−1</sup>, due to strong Ti segregation. These findings provide relationships between cooling rate, microstructure, segregation, and phase formation in K439B alloy, allowing for more precise process optimization and more consistent casting quality.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 189-201"},"PeriodicalIF":6.6,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In-situ detection of powder bed defects in laser powder bed fusion using 3D surface normals and depth mapping 基于三维表面法线和深度映射的激光粉末床熔合中的粉末床缺陷原位检测

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-10 DOI: 10.1016/j.jmrt.2025.09.062

Yuze Zhang , Pan Zhang , Hui Li , Zhongwei Li , Kai Zhong , Yusheng Shi

{"title":"In-situ detection of powder bed defects in laser powder bed fusion using 3D surface normals and depth mapping","authors":"Yuze Zhang , Pan Zhang , Hui Li , Zhongwei Li , Kai Zhong , Yusheng Shi","doi":"10.1016/j.jmrt.2025.09.062","DOIUrl":"10.1016/j.jmrt.2025.09.062","url":null,"abstract":"<div><div>Laser Powder Bed Fusion (LPBF) is one of the most extensively studied metal additive manufacturing processes. Owing to its capabilities in achieving high manufacturing precision, excellent surface quality, and producing complex geometries, it has gained widespread adoption in industries including shipbuilding, automotive, and aerospace. During the LPBF process, powder bed defects are among the most common types of manufacturing defects. However, researchers face major challenges due to the scarcity of in-situ monitoring methods and limited diversity in monitoring data. Optical measurement techniques offer high precision, efficiency, and non-contact operation for in-situ LPBF monitoring. This study proposes an in-situ powder bed monitoring method for LPBF based on a dual-sensor fusion of photometric stereo and structured light measurement. From the raw images captured by sensors, normal maps and depth difference maps are computed, and an enhanced image is synthesized. Multiple quantitative metrics are used to evaluate the effectiveness of the synthesized images in visualizing powder bed defects. The results show that, compared to grayscale images, the synthesized images exhibit significant enhancements of over 65.5 %, 39.8 %, and 147.0 % in entropy, average gradient, and variance, respectively, demonstrating the effectiveness of the proposed fusion strategy in enhancing defect visualization. This achievement provides researchers in the LPBF field with richer in-situ monitoring data and contributes to further defect reduction and improvement in manufacturing precision.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 792-800"},"PeriodicalIF":6.6,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High frequency insulation performance of multi-dimensional modified polyimide composite films of aluminum nitride and boron nitride 氮化铝和氮化硼多维改性聚酰亚胺复合膜的高频绝缘性能

IF 6.6 2区材料科学

Journal of Materials Research and Technology-Jmr&t Pub Date : 2025-09-10 DOI: 10.1016/j.jmrt.2025.09.073

Guowei Hou, Yunpeng Zhang, Li Zhang, Guan Wang, Yiwei Wang

{"title":"High frequency insulation performance of multi-dimensional modified polyimide composite films of aluminum nitride and boron nitride","authors":"Guowei Hou, Yunpeng Zhang, Li Zhang, Guan Wang, Yiwei Wang","doi":"10.1016/j.jmrt.2025.09.073","DOIUrl":"10.1016/j.jmrt.2025.09.073","url":null,"abstract":"<div><div>Polyimide (PI) is widely used as interturn insulation in solid-state transformers (SSTs) for its corona resistance, but its low thermal conductivity and high dielectric loss cause performance degradation under long-term high-frequency electrothermal stress. Adopting multi-dimensional modification design is an effective solution. In this paper, single-dimensional aluminum nitride (AlN) and multi-dimensional aluminum nitride and boron nitride (AlN-BN) modified PI composites were prepared. The surface of the filler was modified by polydopamine (PDA) and the KH550 silane coupling agent. Through microstructural analysis, thermal and mechanical characterization and high-frequency insulation testing, the enhancement mechanism of high-frequency insulation by the multi-dimensional modification was revealed from the aspects of thermal conductivity, dielectric properties, electrical conductivity and trap characteristics. The results show that the AlN-BN/PI composites exhibits enhancements in thermal conductivity, mechanical properties and high-frequency insulation performance. At 10 wt%, the thermal conductivity of AlN-BN/PI composites increases to 0.311 W/(m·K) (85.12 % higher than pure PI and 26.42 % higher than AlN/PI). Under 3 kV/20 kHz, the 10 wt% AlN-BN/PI composites achieves a corona aging lifetime of 69.12 min, (372 % higher than pure PI and 42 % higher than AlN/PI). The enhanced insulation performance of the multi-dimensional composites is attributed to: 1) the AlN-BN \"sphere–sheet wrapping\" structure constructs a thermal conduction network and mitigates dielectric mismatch and loss; 2) multi-dimensional modification enhances charge dynamics through elevated conductivity and shallow trap density, effectively suppressing electric field distortion. These findings advance insulation system optimization for solid-state transformers.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"39 ","pages":"Pages 59-74"},"PeriodicalIF":6.6,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0