Powder Technology最新文献_第2页

Fracture plugging failure under oil-based drilling fluids condition in deep geoenergy formations: A mesoscopic mechanical structure evolution perspective 深层地能地层油基钻井液条件下的裂缝封堵失效：细观力学结构演化视角

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-06 DOI: 10.1016/j.powtec.2025.121730

Xiaopeng Yan , Maojiang Li , Song Deng , Chengyuan Xu , Mingguo Peng , Haoran Jing , Xinran Lian , Wujun Li , Zhenjiang You

{"title":"Fracture plugging failure under oil-based drilling fluids condition in deep geoenergy formations: A mesoscopic mechanical structure evolution perspective","authors":"Xiaopeng Yan , Maojiang Li , Song Deng , Chengyuan Xu , Mingguo Peng , Haoran Jing , Xinran Lian , Wujun Li , Zhenjiang You","doi":"10.1016/j.powtec.2025.121730","DOIUrl":"10.1016/j.powtec.2025.121730","url":null,"abstract":"<div><div>The structural integrity of the particle plugging zone directly affects the success of drilling operations in oil, gas, and geothermal reservoirs through its ability to withstand tectonic pressures. The impact of oil - based drilling fluids on the structural stability of the fracture plugging zone is crucial for preventing leakage during the drilling process. This study employs photoelastic experiments to investigate force chain evolution in rigid particle plugging zones under dry, water-based, and oil-based conditions. Results show distinct behaviors: dry conditions exhibit linear pressure increases followed by decline, water-based conditions show fluctuating trends, and oil-based conditions stabilize after multiple fluctuations with the lowest pressure-bearing capacity. Weak force chains dominate numerically. Under load, strong and medium force chains increase. The key point is that under oil-based conditions, the strong force chain network is relatively sparse, with the dominant orientation being 60°; orientations along 0° and 240° are less prevalent. This makes it difficult to form a fishbone-like high-pressure-bearing structure, and the reduced topological complexity results in poor stability. The evolution of force chain energy is influenced by fluid properties: the decrease in friction leads to particle displacement and structural damage, which compromise the integrity of the force chain structure, induce local fracture failure, and consequently trigger macroscopic failure. Modifying particle properties and integrating tackifiers can enhance force chain networks, improving plugging zone stability and shear strength. These findings offer practical strategies for optimizing drilling fluid systems in deep fractured reservoirs.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121730"},"PeriodicalIF":4.6,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation and experimental study of radial jet blowing–suction air curtain dust control technology in auxiliary haulage roadways of coal mines 煤矿辅助运输巷道径向射流吹吸风幕除尘技术的仿真与试验研究

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-04 DOI: 10.1016/j.powtec.2025.121709

Deji Jing , Qisheng Kan , Yabin Li , Shuaishuai Ren , Mingxing Ma , Jichuang Ma , Ping Chang

{"title":"Simulation and experimental study of radial jet blowing–suction air curtain dust control technology in auxiliary haulage roadways of coal mines","authors":"Deji Jing , Qisheng Kan , Yabin Li , Shuaishuai Ren , Mingxing Ma , Jichuang Ma , Ping Chang","doi":"10.1016/j.powtec.2025.121709","DOIUrl":"10.1016/j.powtec.2025.121709","url":null,"abstract":"<div><div>The widespread adoption of trackless rubber-tyred vehicles in coal mines enhances production efficiency but exacerbates dust pollution in auxiliary haulage roadways, endangering workers' health. To effectively solve this problem, we developed a radial jet blowing–suction air curtain dust control technology. Through numerical simulations, the effects of the jet velocity and blowing duct arrangement on dust control performance were analyzed, identifying optimal dust control parameters: a 25 m/s jet velocity with a blowing duct at position B (0.8 m behind the side directly facing the suction duct). An experimental platform was established on the basis of similarity theory. Through smoke tracing and dust control experiments, single air curtain and blowing–suction air curtain were compared, further validating their effectiveness. Finally, by applying radial jet blowing–suction air curtain dust control technology to the auxiliary haulage north roadway of the Qipanjing Coal Mine, air curtain performance tests were conducted. The dust removal efficiency behind the air curtain exceeded 85 %, whereas the dust removal efficiency ahead of the air curtain exceeded 90 %, which was significantly higher than that behind it. Additionally, for the same test cross-section, the dust removal efficiency increases closer to the blowing outlet. The newly developed air curtain dust control technology provides an effective method for controlling dust in coal mine auxiliary haulage roadways.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121709"},"PeriodicalIF":4.6,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation of chemical looping combustion applying solar energy to a dual circulating fluidized bed reactor 双循环流化床反应器太阳能化学循环燃烧数值模拟

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-04 DOI: 10.1016/j.powtec.2025.121720

Juhui Chen , Shuxiang Pang , Dan Li , Ying Mao , Michael Zhurakov , Siarhei Lapatsin , Wenrui Jiang

{"title":"Numerical simulation of chemical looping combustion applying solar energy to a dual circulating fluidized bed reactor","authors":"Juhui Chen , Shuxiang Pang , Dan Li , Ying Mao , Michael Zhurakov , Siarhei Lapatsin , Wenrui Jiang","doi":"10.1016/j.powtec.2025.121720","DOIUrl":"10.1016/j.powtec.2025.121720","url":null,"abstract":"<div><div>This study presents a theoretical model for coupled flow and heat transfer processes in a dual circulating fluidized bed reactor for solar energy applications. A mathematical simulation of gas-solid two-phase flow is conducted using the Eulerian-Eulerian method, incorporating chemical reactions within the system. Computational fluid dynamics (CFD) is employed to simulate the integrated process of solar-assisted flow, heat transfer, and chemical reactions inside the reactor. The distribution patterns of particles and gas products, the heat transfer characteristics between the two reactors, and the transient behavior of particles in the solid recirculation loop are analyzed. The effects of varying solar radiation flux and air inlet velocity on the reactor's coupled flow and heat transfer characteristics are compared. Results indicate that particle volume fraction and particle velocity in the recirculation loop increase with higher radiation flux or air inlet velocity. Gas product concentrations also increase as the reaction proceeds, and higher solid particle temperatures are observed in regions with greater particle accumulation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121720"},"PeriodicalIF":4.6,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analytical study of the trend in the field of factors affecting the viscosity of nanofluids and evaluation of their rheological behavior under different conditions during the years (2013-2023): Scientometric analysis 2013-2023年纳米流体粘度影响因素趋势分析研究及不同条件下流变行为评价：科学计量学分析

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-03 DOI: 10.1016/j.powtec.2025.121673

Mohammad Hemmat Esfe , Seyed Naser Hosseini Tamrabad , Davood Toghraie

{"title":"Analytical study of the trend in the field of factors affecting the viscosity of nanofluids and evaluation of their rheological behavior under different conditions during the years (2013-2023): Scientometric analysis","authors":"Mohammad Hemmat Esfe , Seyed Naser Hosseini Tamrabad , Davood Toghraie","doi":"10.1016/j.powtec.2025.121673","DOIUrl":"10.1016/j.powtec.2025.121673","url":null,"abstract":"<div><div>This review examines nanofluid viscosity research (2013-2023) by analyzing 5261 articles to identify the best in the field and provide a path for the future of the field. The findings show that the publication of articles has been on an upward trend, indicating the importance of this field in the industry. Physics and astronomy, engineering, and chemical engineering were the most widely used subject areas. Prominent researchers such as Hemmat Esfe, Toghraei, and Sheikholesalami have played the most prominent roles in this research. India, Iran, and China are at the top of the field of carbon nanotube viscosity, respectively, with the highest number of published documents. Saudi Arabia and Egypt have led the way in intercontinental collaborations with 80 international collaborations. The Journal of Molecular Fluids (253 articles) and the Journal of Heat and Mass Transfer (13,153 citations) were identified as the top journals in this field. The most frequently used keywords included nanofluids, viscosity, and rheological behavior. This study provides guidance for researchers and policymakers for future research.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121673"},"PeriodicalIF":4.6,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling particle mixing from non-destructive 3D XCT imaging with machine learning aided spatial distribution analysis 通过机器学习辅助空间分布分析，揭示非破坏性3D XCT成像中的粒子混合

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-03 DOI: 10.1016/j.powtec.2025.121699

Leqi Lin , Kaiyuan Yang , Xingyu Zhou , Mingzhe Yu , Li Liu , Xizhong Chen

引用次数: 0

Desulfurization of high‑sulfur bauxite through roasting with various additives: phase transformation and micromorphological evolution 不同添加剂对高硫铝土矿焙烧脱硫的影响：相变和微观形态演变

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-02 DOI: 10.1016/j.powtec.2025.121704

Mengnan Li , Zhanwei Liu , Hengwei Yan , Wenhui Ma , Zhanliang Yu , Mingyi Hu , Jiaping Zhao

{"title":"Desulfurization of high‑sulfur bauxite through roasting with various additives: phase transformation and micromorphological evolution","authors":"Mengnan Li , Zhanwei Liu , Hengwei Yan , Wenhui Ma , Zhanliang Yu , Mingyi Hu , Jiaping Zhao","doi":"10.1016/j.powtec.2025.121704","DOIUrl":"10.1016/j.powtec.2025.121704","url":null,"abstract":"<div><div>The high‑sulfur content of bauxite presents a significant challenge in alumina production. This study explored oxidative roasting as a desulfurization strategy, examining the effects of roasting temperature, duration, and various additives on sulfur removal. The results indicated that under conditions of 600 °C for 120 min without additives, the sulfur mass fraction in the roasted bauxite decreased from 16.63 % to 0.27 %, achieving a sulfur removal rate of 98.75 %. The addition of O<sub>2</sub> enhanced desulfurization efficiency. At 500 °C for 120 min with an O<sub>2</sub> flow rate of 1.2 g/min, sulfur content decreased to 0.66 %, corresponding to a 96.83 % removal rate, which was 26.53 % higher compared with that achieved without O<sub>2</sub> assistance. However, when NaNO<sub>3</sub> and Na<sub>2</sub>O<sub>2</sub> were introduced, the formation of Na<sub>2</sub>SO<sub>3</sub>, NaFeS<sub>2</sub>, and Na<sub>2</sub>SO<sub>4</sub> significantly suppressed sulfur release. Furthermore, upon using various modern analytical techniques, the study investigated mineralogical characteristics, phase transformations, chemical composition, and microstructural evolution of bauxite before and after roasting. Results indicated that pyrite, the primary sulfur-bearing phase, decomposed to Fe<sub>2</sub>O<sub>3</sub> and SO<sub>2</sub>. Notably, both additive-free and O<sub>2</sub>-assisted roasting increased surface roughness, porosity, and crack formation of the bauxite, which enhanced its digestion performance.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121704"},"PeriodicalIF":4.6,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Particle breakage behavior of recycled construction and demolition waste mixed aggregates during compaction and biaxial compression 建筑和爆破垃圾混合集料在压实和双轴压缩过程中的颗粒破碎行为

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-02 DOI: 10.1016/j.powtec.2025.121698

Xiaowei Gu , Zhenguo Zhu , Jianping Liu , Fan Yang , Xiaochuan Xu , Shenyu Wang , Kai Zhan

{"title":"Particle breakage behavior of recycled construction and demolition waste mixed aggregates during compaction and biaxial compression","authors":"Xiaowei Gu , Zhenguo Zhu , Jianping Liu , Fan Yang , Xiaochuan Xu , Shenyu Wang , Kai Zhan","doi":"10.1016/j.powtec.2025.121698","DOIUrl":"10.1016/j.powtec.2025.121698","url":null,"abstract":"<div><div>The breakage behavior of construction and demolition waste (CDW) materials significantly impacts the mechanical performance of pavement base courses. In this study, a DEM model was employed to simulate the compaction and biaxial compression of recycled CDW base-course filler. The model was parameterized using compaction and sieving tests and morphology analysis, explicitly accounting for particle shape, gradation, and mix proportion. By integrating laboratory and numerical results, the mesoscopic breakage mechanisms and their evolution during compaction and post-compaction biaxial compression were systematically revealed. Results show that the mixing ratios of recycled concrete aggregate (RCA), recycled brick aggregate (RBA), and recycled mortar aggregate (RMA), as well as the particle size distributions of RCA and RBA, primarily determine the crushing behavior of the mixture. RBA and RMA are the main sources of breakage. Smaller RBA particles are more susceptible to pulverization, which increases the bond breakage ratio but reduces the volumetric breakage ratio. Higher RBA content and smaller RBA size further accelerate bond breakage during post-compaction biaxial compression. RCA serves as the skeleton, forming main force chains, while RBA and RMA form secondary chains that help redistribute and alleviate breakage of RCA. Optimizing RCA proportion and RBA size improves compactness and stability. When the mix ratio of RCA: RBA: RMA is 6:3:1 and RBA particle size is less than 9.5 mm, maximum dry density and optimal mechanical performance are achieved. These findings provide theoretical and practical support for mix ratio optimization and engineering application of recycled CDW pavement base fillers.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121698"},"PeriodicalIF":4.6,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Near-zero carbon iron powder from high‑phosphorus oolitic pellets via hydrogen reduction-electromagnetic iron phase reconstruction - magnetic separation 高磷鲕粒经氢还原—电磁铁相重构—磁分离制备近零碳铁粉

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-02 DOI: 10.1016/j.powtec.2025.121719

Mengjie Hu , Deqing Zhu , Jian Pan , Siwei Li

{"title":"Near-zero carbon iron powder from high‑phosphorus oolitic pellets via hydrogen reduction-electromagnetic iron phase reconstruction - magnetic separation","authors":"Mengjie Hu , Deqing Zhu , Jian Pan , Siwei Li","doi":"10.1016/j.powtec.2025.121719","DOIUrl":"10.1016/j.powtec.2025.121719","url":null,"abstract":"<div><div>To overcome the limitations of conventional carbothermic reduction—specifically its high carbon footprint and the inefficient treatment of finely disseminated iron minerals in high‑phosphorus oolitic iron ore (HPOIO)—this study introduces an innovative process combining hydrogen reduction, electromagnetic induction heating, and magnetic separation. Under optimized reduction conditions (950 °C, 90 min, 10 L/min H₂ flow), the oxidized pellets attained a metallization degree of 85.56 %. A profound microstructural transformation was achieved via electromagnetic induction heating at 1350 °C for 30 min, which resulted in an approximately 16-fold increase in the average equivalent circular diameter of the metallic iron grains, from an initial 1.19 μm to a final 19.03 μm. This microstructural evolution, driven by recrystallization and phase rearrangement, converted finely dispersed iron phases into coarse vermicular and massive aggregates, markedly improving slag–metal separation. The efficacy of the induction treatment was demonstrated by a substantial upgrade in the magnetic concentrate. This was evidenced by an elevation of the iron grade to 91.18 % from an initial 59.57 %, a concomitant drop in phosphorus content to 0.09 % from 0.26 %, and a resultant surge in dephosphorization efficiency to 79.77 % from 12.14 %. The integrated approach demonstrates a viable near-zero-carbon route for converting HPOIO into high-grade, low-phosphorus iron powder via hydrogen-based direct reduction and precisely controlled iron phase reconstruction.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121719"},"PeriodicalIF":4.6,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxidation mechanism of single char particles: Insights from chemical imaging by micro-Raman mapping technique in a heating stage 单炭颗粒的氧化机制：在加热阶段通过微拉曼映射技术从化学成像的见解

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-02 DOI: 10.1016/j.powtec.2025.121724

Ming Jiang , Jun Xu , Yuming Ding , Kai Xu , Long Jiang , Yi Wang , Sheng Su , Song Hu , Jun Xiang

{"title":"Oxidation mechanism of single char particles: Insights from chemical imaging by micro-Raman mapping technique in a heating stage","authors":"Ming Jiang , Jun Xu , Yuming Ding , Kai Xu , Long Jiang , Yi Wang , Sheng Su , Song Hu , Jun Xiang","doi":"10.1016/j.powtec.2025.121724","DOIUrl":"10.1016/j.powtec.2025.121724","url":null,"abstract":"<div><h3>Abstract</h3><div>This study developed a Raman-mapping method to visualize individual char particles during oxidation, tracking the spatiotemporal evolution of their chemical structure. 3 series of experiments were conducted: (i) micro-scale mapping of 1000 °C chars before oxidation to quantify inherent heterogeneity of the char particles, (ii) Raman mapping at room temperature after stepwise oxidation to resolve the progressive structural evolution during the char oxidation, and (iii) high-temperature in situ Raman spectroscopy of single char particle and char particle clusters to follow real-time carbon framework evolution and functional group formation during the oxidation sequence. The results show that Hongshaquan coal char pyrolyzed at 1000 °C exhibits intra- and inter-particle structural variation, with individual heterogeneity peaking when the particle's average structure approaches that of the bulk char. Besides, oxidation reactivity of the char correlates more strongly with char surface heterogeneity than with average structural parameters. During the char oxidation, its structures proceed in 3 stages: (i) O<sub>2</sub> attacks side chains and small aromatic rings, cleaving large aromatic rings and raising the fraction of oxygen-containing functional groups and small aromatic rings. (ii) These species accumulate to a peak and then deplete. (iii) A mineral-rich ash shell forms in the later stage of the oxidation, hindering oxygen diffusion and slowing down the oxidation of residual carbon. Single-particle oxidation results can capture the complete oxidation process and its chemical structure evolution, whereas particle clusters burn layer-by-layer, easily overlooking the early activation process. This study can provide a deep understanding on the oxidation mechanism of char single-particles.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121724"},"PeriodicalIF":4.6,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","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 La2O3 addition on preparation of ultrafine tungsten powder and its sintering densification behavior La2O3对超细钨粉制备及其烧结致密化性能的影响

IF 4.6 2区工程技术

Powder Technology Pub Date : 2025-10-01 DOI: 10.1016/j.powtec.2025.121705

Peng-Cheng Cai , Bao-Jiang Ren , Xin-Wen Zhou , Guo-Hua Zhang , Kuo-Chih Chou

{"title":"Effect of La2O3 addition on preparation of ultrafine tungsten powder and its sintering densification behavior","authors":"Peng-Cheng Cai , Bao-Jiang Ren , Xin-Wen Zhou , Guo-Hua Zhang , Kuo-Chih Chou","doi":"10.1016/j.powtec.2025.121705","DOIUrl":"10.1016/j.powtec.2025.121705","url":null,"abstract":"<div><div>Tungsten and its alloys occupy a critical position in modern defense, nuclear energy, vacuum electronics, and lighting applications due to their unique and irreplaceable properties. However, the intrinsic brittleness, thermal shock brittleness, and recrystallization brittleness of tungsten significantly limit its application and development. To address the high brittleness and poor strength-toughness of tungsten, the present work aimed to first prepare La<sub>2</sub>O<sub>3</sub> dispersion-strengthened composite powders by spray drying‑hydrogen reduction process. Subsequently, highly dense ultrafine-grained dispersion-strengthened W alloys were fabricated via spark plasma sintering (SPS). It was indicated that La<sub>2</sub>O<sub>3</sub> exhibited a significant refining effect on the powder; however, excessive La<sub>2</sub>O<sub>3</sub> addition led to aggregation, promoting the chemical vapor transport (CVT) mechanism and ultimately causing powder coarsening. During the sintering process, the uneven distribution and aggregation of secondary phase particles diminished their grain refinement capability. The resulting nanostructured W-0.5La<sub>2</sub>O<sub>3</sub> (wt%) composite powder exhibited a grain size of 109 nm, while the W-0.5La<sub>2</sub>O<sub>3</sub> alloy possessed the highest Vickers hardness of 647.9 HV<sub>0.2</sub>. Furthermore, the reduction and densification mechanisms of composite powder were investigated in detail.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"469 ","pages":"Article 121705"},"PeriodicalIF":4.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0