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Journal of Materials Science & Technology 2013年第11期29卷 1067-1073页

作者： Haibin Wang Xiaoyan Song chongbin wei Yang Gao Guangsheng Guo College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of Technology

The ultrafine WC-Co composite powder was synthesized by a newly developed rapid route based on in situ reactions. By using the as-synthesized composite powder, the granulation processing was then carried out to prepare the ultrafine-structured thermal spraying feedstock. The influences of the heat-treatment process on density of the feedstock powder, phase constitution and wear resistance of the resultant WC-Co coatings fabricated by high velocity oxy-fuel （HVOF） were investigated. The results showed that increasing the heating temperature and extending the holding time leaded to remarkable increase in the density and flowability of the feedstock powder. As a result, the decarburization of the in-flight particles could be decreased and the wear resistance of coating was significantly enhanced. The present study demonstrated that the developed techniques for the ultrafine powder and its thermal-sprayed coatings had very promising applications in scaling up to produce ultrafine-structured cermet coatings with excellent performance.

关键词： WC-Co composite powder Decarburization Density Ultrafine-structured coating Abrasion resistance

Effect of Carbon Addition on Microstructure and Properties of WC-Co Cemented Carbides

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Journal of Materials Science & Technology 2012年第9期28卷 837-843页

作者： chongbin wei Xiaoyan Song Jun Fu Xiaosen Lv Haibin Wang Yang Cao ShixianZhao Xuemei Liu College of Materials Science and Engineering Key Lab of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of TechnologyBeijing 100124China Beijing Belying Hardalloy Co. Ltd.Beijing 100055China

Based on a unique method to synthesize WC-Co composite powder by in-situ reactions of metal oxides and carbon, the effects of the carbon addition in the initial powders on the phase constitution, microstructure and mechanical properties of the cemented carbides were investigated. It is found that with a suitable carbon addition the pure phase constitution can be obtained in the sintered bulk from the composite powder. The mechanical properties of the cemented carbides depend on the phase constitution and the WC grain structure. To obtain the excellent properties of the WC-Co bulk, it is important to obtain the pure phase constitution from the appropriate carbon addition in the initial powders and a suitable grain size.

关键词： Cemented carbides Carbon addition Composite powder Phase constitution Mechanical property

碳化帆颗粒尺寸对纳米晶硬质合金组织和性能的影响

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稀有金属材料与工程 2014年第5期43卷 1224-1228页

作者：高杨宋晓艳刘雪梅王海滨魏崇斌北京工业大学新型功能材料教育部重点实验室北京100124

利用原位还原碳化反应制备纳米尺度的WC-Co复合粉体,应用放电等离子烧结(SPS)技术制备出纳米晶WC-Co硬质合金块体材料。分析了晶粒长大抑制剂碳化钒(VC)颗粒尺寸对纳米晶硬质合金的显微组织、晶粒尺寸及分布和力学性能的影响。结果表明:... 详细信息

利用原位还原碳化反应制备纳米尺度的WC-Co复合粉体,应用放电等离子烧结(SPS)技术制备出纳米晶WC-Co硬质合金块体材料。分析了晶粒长大抑制剂碳化钒(VC)颗粒尺寸对纳米晶硬质合金的显微组织、晶粒尺寸及分布和力学性能的影响。结果表明:当VC的粒径减小到100 nm以下时,利用快速烧结技术可制备得到平均晶粒尺寸约为70 nm的致密WC-Co硬质合金块体材料,其物相纯净,晶粒尺寸分布均匀,维氏硬度为19.84 GPa,断裂韧性达到12.10 MPa·m1/2。

关键词：纳米晶WC-Co块体 VC颗粒尺寸力学性能

复合添加晶粒长大抑制剂对WC-Co复合粉烧结硬质合金的影响

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稀有金属材料与工程 2014年第8期43卷 1928-1934页

作者：付军宋晓艳魏崇斌刘雪梅王海滨高杨王瑶北京工业大学新型功能材料教育部重点实验室北京100124

在超细WC-Co复合粉中复合添加不同含量的晶粒长大抑制剂VC和Cr3C2,利用X射线衍射仪分析粉末及硬质合金的物相组成,通过扫描电镜和透射电镜观察硬质合金的形貌,研究不同含量的晶粒长大抑制剂对硬质合金的显微组织和力学性能影响规律。结... 详细信息

在超细WC-Co复合粉中复合添加不同含量的晶粒长大抑制剂VC和Cr3C2,利用X射线衍射仪分析粉末及硬质合金的物相组成,通过扫描电镜和透射电镜观察硬质合金的形貌,研究不同含量的晶粒长大抑制剂对硬质合金的显微组织和力学性能影响规律。结果表明:随着晶粒长大抑制剂的增加,晶粒异常长大现象消失,晶粒细小均匀;同时发现在WC-Co复合粉中VC的增加可以快速提高硬质合金的硬度,而适量的Cr3C2可以有效提高硬质合金的横向断裂强度。

关键词：复合晶粒长大抑制剂超细WC-Co复合粉显微组织力学性能

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高性能再生硬质合金的短流程回收制备

金属学报 2014年第5期50卷 633-640页

作者：王瑶刘雪梅宋晓艳魏崇斌王海滨王西龙北京工业大学材料科学与工程学院新型功能材料教育部重点实验室北京100124

以WC-16%Co(质量分数)废旧硬质合金块体为原料,采用氧化-原位还原碳化的方法对其进行回收制备再生WC-16%Co复合粉,并对再生复合粉进行低压烧结制备再生硬质合金块体材料.通过热力学计算确定氧化物粉末和炭黑发生原位还原碳化反应的温度... 详细信息

以WC-16%Co(质量分数)废旧硬质合金块体为原料,采用氧化-原位还原碳化的方法对其进行回收制备再生WC-16%Co复合粉,并对再生复合粉进行低压烧结制备再生硬质合金块体材料.通过热力学计算确定氧化物粉末和炭黑发生原位还原碳化反应的温度范围,采用实验方法系统研究了原料粉末中配C量对再生复合粉和再生硬质合金的物相组成、力学性能等的影响,并对再生合金的显微组织与性能的关系进行了分析.结果表明:随着原料粉中配C量的增加,再生复合粉中的Co6W6C相逐渐减少,总C和游离C含量增加;当配C量为16.60%时,可制备出化学成分符合原生WC-16%Co复合粉要求的再生复合粉,经低压烧结可得到物相纯净,断裂韧性达到23.05 MPa·m1/2,横向断裂强度达到4020 MPa的高性能再生硬质合金;再生硬质合金的Co相分布是否均匀,对再生硬质合金的综合性能优良与否起到至关重要的作用.

关键词：废旧硬质合金回收配C量 WC—Co复合粉力学性能

A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： wei wei Feng GUAN Xin FANG College of Intelligent Science National University of Defense TechnologyChangsha410073China Naval Research Academy Beijing100161China

A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave *** consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and *** bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are *** experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate

The lithology and composition of lunar mantle modifi ed by ilmenite bearing cumulate: A thermodynamic model

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Acta Geochimica 2024年第5期43卷 856-875页

作者： wei Huang wei Du State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of Sciences University of Chinese Academy of Sciences Center for Excellence in Comparative Planetology Chinese Academy of Sciences

Due to their high density,the ilmenite-bearing cumulates (IBC)(with or without KREEP) formed during the late-stage lunar magma ocean solidifi cation are thought to sink into the underlying lunar mantle and trigger lunar mantle *** evidence implied that IBC may descend deep inside the Moon and remain as a partially molten layer at the core-mantle boundary (CMB).However,partial melting may have occurred on the mixed mantle cumulates during the sinking of IBC/KREEP and the silicate melt may be positively buoyant,thus preventing the IBC/KREEP layer from sinking to the ***,we perform thermodynamic simulation on the stability of lunar mantle cumulates at diff erent depths mixed with diff erent amounts of IBC/KREEP from an updated LMO *** modeling results suggest that the sinking of IBC/KREEP will cause at least 5 wt%partial melting in the shallow (～120 km) and a much larger degree of partial melting in the deep lunar mantle (～420 km).Due to the density contrast with the surrounding mantle,IBC/KREEP-bearing melts could potentially decouple under certain *** modifi ed lunar mantle by sinking of IBC/KREEP can better explain the formation of diff erent kinds of lunar basaltic magma than the primary lunar mantle formed through diff erentiation of lunar magma *** of IBC/KREEP back into the lunar mantle may introduce plagioclase,clinopyroxene,garnet,and incompatible radioactive elements into the deep lunar mantle,which will further aff ect the thermal and chemical evolution of the lunar interior.

关键词： Ilmenite-bearing cumulate KREEP Lunar mantle overturn Partial melting pMELTS

Humic acid-mediated transport of a typical soil passivation remediation product(chloropyromorphite)in saturated porous media

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Journal of Environmental Sciences 2024年第7期141卷 51-62页

作者： Xinying Li Mengjia Zhang Siyuan Li wei wei School of Environment Jiangsu Engineering Lab of Water and Soil Eco-remediationJiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response TechnologyNanjing Normal UniversityNanjing 210023China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023China

Conversion of labile Pb species into chloropyromorphite(CPY)using phosphorus-bearing amendments was considered to be an ideal strategy in soil passivation ***,the fate and transport of CPY in the soil are poorly *** study aims to fill the knowledge gap by evaluating the fate and transport of CPY under environmentally relevant conditions of humic acid(HA),pH,electrolyte concentration,and species through the saturated sandy *** showed that bare CPY colloids are basically immobile in sandy porous media while the co-existence of HA made the transport of CPY improved by30%-93.5%.Facilitated transport of CPY was attributed to the increased stability of CPY and the repulsive interaction between CPY particles and sands due to HA *** mobility of CPY was also increased with increasing pH from 5.0 to *** the pH was 9 with a10 mmol/L NaCl background solution,the stronger energy barrier between CPY and sand led to enhanced transport *** divalent Ca^(2+)had a more dramatic effect than monovalent Na^(+)on the aggregation and sedimentation of CPY colloids due to its effectivescreening of the surface charge of CPY and bridging interaction with CPY ***-LandauVerwey-Overbeek theory and attachment efficiency calculation indicated that high energy barriers were responsible for the high mobility of CPY colloids,while the retention of CPY in sands was mainly caused by secondary energy minimum and physically *** findings of this work can help to evaluate the fate of soil passivation remediation products in natural water and soil.

关键词： Chloropyromorphite DLVO theory Stability Saturated porous medium Transport

The Existence of a Meridional Curve in Closed Incompressible Surfaces in Fully Alternating Link Complements

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 73-80页

作者： wei LIN School of Mathematical Sciences Dalian University of TechnologyDalian 116024LiaoningChina

Menasco showed that a closed incompressible surface in the complement of a non-split prime alternating link in S^(3) contains a circle isotopic in the link complement to a meridian of the *** on this result,he was able to argue the hyperbolicity of non-split prime alternating links in *** et *** that if F■S×I\L is an essential torus,then F contains a circle which is isotopic in S×I\L to a meridian of *** author generalizes his result as follows:Let S be a closed orientable surface,L be a fully alternating link in S×I\If F ■ S×I\L is a closed essential surface,then F contains a circle which is isotopic in S×I\L to a meridian of L.

关键词： Fully alternating Incompressible surfaces Meridionally incompressible

氧化‐还原碳化法回收再生高性能硬质合金的研究

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稀有金属材料与工程 2014年第12期43卷 3172-3176页

作者：王瑶宋晓艳刘雪梅魏崇斌王海滨王西龙付军北京工业大学新型功能材料教育部重点实验室北京100124

以废旧WC-Co硬质合金为原料,采用氧化和原位还原碳化的短流程方法合成再生WC-Co复合粉末,随后对再生复合粉低压烧结得到再生硬质合金。利用XRD、SEM和TEM等对再生复合粉和再生硬质合金的物相和显微组织形貌进行观察和分析,系统研究了原... 详细信息

以废旧WC-Co硬质合金为原料,采用氧化和原位还原碳化的短流程方法合成再生WC-Co复合粉末,随后对再生复合粉低压烧结得到再生硬质合金。利用XRD、SEM和TEM等对再生复合粉和再生硬质合金的物相和显微组织形貌进行观察和分析,系统研究了原料粉末中配碳量对再生复合粉和再生合金的物相组成和力学性能的影响。配碳量为16.60%时制备的再生WC-16%Co(质量分数,下同)硬质合金的断裂韧性为24.80 MPa·m1/2、横向断裂强度达到3860MPa,并且分析了再生硬质合金的显微组织与性能之间的关系。

关键词：硬质合金回收 WC-Co复合粉配碳量烧结