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基于SiIGBT与SiCFET并联的新型混合器件特性解析及对比研究 被引量:1
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作者 朱梓贤 涂春鸣 +3 位作者 肖标 郭祺 肖凡 龙柳 《太阳能学报》 北大核心 2025年第1期251-260,共10页
对由SiC FET与Si IGBT并联组成的新型混合器件(HY_F)开展研究。首先,分析HY_F的基本结构与工作原理,并搭建HY_F的导通损耗模型、开通损耗模型以及关断损耗模型。其次,基于混合器件的仿真模型,分析HY_F与传统Si IGBT/SiC MOSFET混合器件(... 对由SiC FET与Si IGBT并联组成的新型混合器件(HY_F)开展研究。首先,分析HY_F的基本结构与工作原理,并搭建HY_F的导通损耗模型、开通损耗模型以及关断损耗模型。其次,基于混合器件的仿真模型,分析HY_F与传统Si IGBT/SiC MOSFET混合器件(HY_M)在不同额定电流等级下损耗与成本的优劣势。仿真结果表明,当额定电流为较小(15 A)时,HY_M能以较低的成本实现更低的损耗;混合器件在额定电流较大(25 A、40 A)时,HY_F能以更低的成本实现更低的损耗。最后,通过实验验证结论的正确性。 展开更多
关键词 si/siC混合器件 siCMOSFET siIGBT siCFET 损耗模型
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Reduced graphene oxide assembled on the Si nanowire anode enabling low passivation and hydrogen evolution for long-life aqueous Si-air batteries 被引量:1
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作者 Fengjun Deng Tingyu Zhao +4 位作者 Xiaochen Zhang Kaiyong Feng Ze Liu Youlin Xiang Yingjian Yu 《Chinese Chemical Letters》 2025年第6期688-692,共5页
Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,a... Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,and the anode utilization rate is low.In this work,reduced graphene oxide(RGO)fabricated via high-temperature annealing or L-ascorbic acid(L.AA)reduction was first used to obtain Si nanowires/RGO-1000(Si NWs/RGO-1000)and Si nanowires/RGO-L.AA(Si NWs/RGO-L.AA)composite anodes for SABs.It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 h,breaking the previous performance of SABs,and that the specific capacity was increased by 90.8%compared to bare Si.This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers. 展开更多
关键词 si-air batteries Reduced graphene oxide si NWs PASsiVATION Corrosion
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Design strategies of Si-based anode for solid-state batteries
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作者 Peining Zhu Xi Guo +6 位作者 Qinqin Yu Zuyong Wang Xiangxiao Lei Zhiwei Zhu Juan Du Xiaojia Zhang Yuan-Li Ding 《Chinese Chemical Letters》 2025年第9期198-222,共25页
Solid-state lithium-ion batteries(SSLIBs) offer significant advantages over traditional liquid-electrolytebased batteries,including improved safety,higher energy density,and better thermal stability.Among various anod... Solid-state lithium-ion batteries(SSLIBs) offer significant advantages over traditional liquid-electrolytebased batteries,including improved safety,higher energy density,and better thermal stability.Among various anode materials,silicon(Si)-based anodes have attracted significant attention due to their ultrahigh theoretical capacity(~4200 mAh/g) and abundant resources.However,widespread adoption of Si-based anodes in SSLIBs is still restricted by some critical challenges such as severe volume expansion,low electronic and ionic conductivity,high interfacial impedance,and low initial Coulombic efficiency(ICE).This review mainly focuses on the design strategies of Si-based anode for SSLIBs at the material,electrode and cell levels including nanostructuring,Si alloys,Si-carbon composites,conductive additives,advanced binder,external pressure,electrolyte infiltration,and prelithiation.The insights provided here aim to inspire future research and accelerate commercialization of high-performance Si-based anodes in next-generation SSLIBs. 展开更多
关键词 si anode Solid state battery Energy density Power density Design strategy
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考虑驱动参数的Si/SiC混合器件损耗建模研究
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作者 刘平 曹麒 +3 位作者 肖标 肖凡 郭祺 涂春鸣 《湖南大学学报(自然科学版)》 北大核心 2025年第10期133-144,共12页
针对SiC MOSFET与Si IGBT并联构成的Si/SiC混合器件在不同驱动参数下损耗模型精度低问题,提出一种基于驱动参数的损耗建模方法.首先,在两种典型开关时序下分段分析Si/SiC混合器件的暂态过程.其次,基于驱动电压与驱动电阻构建损耗模型.最... 针对SiC MOSFET与Si IGBT并联构成的Si/SiC混合器件在不同驱动参数下损耗模型精度低问题,提出一种基于驱动参数的损耗建模方法.首先,在两种典型开关时序下分段分析Si/SiC混合器件的暂态过程.其次,基于驱动电压与驱动电阻构建损耗模型.最后,搭建双脉冲测试与稳态参数测量实验平台,在不同驱动电阻、不同负载电流与不同驱动电压条件下验证模型的准确性.实验结果表明,开关时序Ⅰ下开通损耗与关断损耗模型的拟合度分别达到97.61%和99.20%;在开关时序Ⅱ下,开通损耗与关断损耗模型的拟合度分别为97.83%和97.66%. 展开更多
关键词 功率半导体器件 siC MOSFET si IGBT 混合器件 损耗 驱动参数
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Si元素质量分数对高速列车用Al-Mg-Si合金MIG焊接接头微观组织与力学性能的影响
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作者 李俊 汪海 +2 位作者 袁忠禹 李欣蓓 叶凌英 《铝加工》 2025年第4期16-24,共9页
制备了Si元素质量分数分别为0.83%和1.38%的两种Al-Mg-Si合金,并开展了熔化极惰性气体保护焊(MIG)接头强度测试,结合数字图像相关(DIC)分析、电子背散射衍射(EBSD)分析和透射电子显微镜(TEM)分析等手段,研究了不同Si元素质量分数对母材... 制备了Si元素质量分数分别为0.83%和1.38%的两种Al-Mg-Si合金,并开展了熔化极惰性气体保护焊(MIG)接头强度测试,结合数字图像相关(DIC)分析、电子背散射衍射(EBSD)分析和透射电子显微镜(TEM)分析等手段,研究了不同Si元素质量分数对母材及焊接接头强度的影响。结果表明,Si元素质量分数分别为0.83%和1.38%的两种合金母材抗拉强度分别为(329.4±1.8)MPa和(377.7±2.3)MPa,MIG焊接接头抗拉强度分别为(258.6±1.9)MPa和(270.1±1.3)MPa,焊接接头系数分别为0.79±0.01和0.72±0.01。Si元素质量分数为1.38%的合金在应变为5%时,应力集中转移至热影响区(HAZ)两侧,导致合金更早发生局部变形,断后伸长率降低。时效后Si元素质量分数分别为0.83%和1.38%的两种合金母材的β″相体积分数分别为0.97%和2.16%,平均尺寸分别为2.94 nm和3.85 nm。两种合金母材析出强化贡献分别为137 MPa和202 MPa,析出强化分别提供了46%和56%的母材强度。 展开更多
关键词 si元素质量分数 AL-MG-si合金 MIG焊接 微观组织
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In-situ Si particle-reinforced joints of hypereutectic Al−60Si alloys by ultrasonic-assisted soldering 被引量:2
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作者 Yuan-xing LI Xiang-bo ZHENG +3 位作者 Chao-zheng ZHAO Zong-tao ZHU Yu-jie BAI Hui CHEN 《Transactions of Nonferrous Metals Society of China》 2025年第1期77-90,共14页
To improve the wettability of hypereutectic Al−60Si alloy and enhance the mechanical properties of the joints,Al−60Si alloy was joined by ultrasonic soldering with Sn-9Zn solder,and a sound joint with in-situ Si parti... To improve the wettability of hypereutectic Al−60Si alloy and enhance the mechanical properties of the joints,Al−60Si alloy was joined by ultrasonic soldering with Sn-9Zn solder,and a sound joint with in-situ Si particle reinforcement was obtained.The oxide film of Al−60Si alloy at the interface was identified by transmission electron microscopy(TEM)analysis as amorphous Al_(2)O_(3).The oxide of Si particles in the base metal was also alumina.The oxide film of Al−60Si alloy was observed to be removed by ultrasonic vibration instead of holding treatment.Si particle-reinforced joints(35.7 vol.%)were obtained by increasing the ultrasonication time.The maximum shear strength peaked at 99.5 MPa for soldering at 330℃with an ultrasonic vibration time of 50 s.A model of forming of Si particles reinforced joint under the ultrasound was proposed,and ultrasonic vibration was considered to promote the dissolution of Al and migration of Si particles. 展开更多
关键词 hypereutectic Al−60si alloy ultrasonic-assisted soldering si particle reinforcement Sn−9Zn solder
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Preparation of Si/NC/CL-20 Composite Explosives by Electrostatic Spraying Method and Its Performance Characterization
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作者 DUAN Yi-long WANG Ling-xin +3 位作者 DONG Jun LI Xiu-long HE Xi JI Wei 《火炸药学报》 北大核心 2025年第5期424-429,I0001,共7页
To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying ... To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying method.The morphology,structure and thermal decomposition properties of the samples were analyzed using scanning electron microscopy(SEM),X-ray energy spectroscopy(EDS),infrared spectroscopy(FT-IR),and simultaneous thermal analyzer(TG-DSC).Additionally,the combustion process of the samples was tested using a high-speed camera.The results show that the addition of nano-Si contributes to the formation of composite explosives with regular morphology and smaller particle size.The Si/NC/CL-20 composite explosive has better and more uniform sphericity,with an average particle size of 73.4 nm,compared to the NC/CL-20 composite explosive.The Si/NC/CL-20 composite explosive which produced by the electrostatic spraying method,achieves physically uniform distribution of the components including NC,CL-20,Si.The addition of Si promotes the thermal decomposition of CL-20.In comparison to the NC/CL-20 composite explosive,the activation energy of the Si/NC/CL-20 composite explosive decreases by 16.78 kJ/mol,and the self-accelerated decomposition temperature and the critical temperature of thermal explosion decreases by 3.12 K and 2.61 K,respectively.Furthermore,Si/NC/CL-20 composite explosive has shorter ignition delay time and faster combustion rate compared to the NC/CL-20 composite explosive,which shows that Si can improve the combustion performance of CL-20. 展开更多
关键词 applied chemistry electrostatic spraying method si si/NC/CL-20 thermal decomposition performance combustion performance
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SiC/Si混合开关时间延迟及其信号调制方法 被引量:2
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作者 丁四宝 王盼宝 +1 位作者 王卫 徐殿国 《电工技术学报》 北大核心 2025年第4期1129-1144,共16页
SiC MOSFET和Si IGBT并联构成的混合开关(SiC/Si HyS)结构是一种优化效率和成本的综合解决方案。依靠SiC MOSFET的低导通时间构建Si IGBT的零电压开通和关断,并继承Si IGBT在高负载电流下的低导通损耗特性,从而提升系统整体效率。为了... SiC MOSFET和Si IGBT并联构成的混合开关(SiC/Si HyS)结构是一种优化效率和成本的综合解决方案。依靠SiC MOSFET的低导通时间构建Si IGBT的零电压开通和关断,并继承Si IGBT在高负载电流下的低导通损耗特性,从而提升系统整体效率。为了更简单高效地生成SiC/Si HyS的SiC MOSFET和Si IGBT驱动信号,该文提出一种针对最小SiC导通模式的信号调制电路,通过配置对应的RC缓冲电路中的电阻、电容值即可调节控制模式中的四个时间尺度,该方法具有灵活简单等优点。首先,理论分析最小SiC导通模式下的SiC/Si HyS结构损耗分布特性;其次,给出信号调制电路原理并介绍信号调制电路的工作原理,建立RC缓冲电路参数和时间尺度之间的函数方程;最后,基于搭建的SiC/Si HyS硬件平台,在双脉冲测试电路中验证最小SiC导通模式下的SiC/Si HyS损耗特性和所提信号调制电路的有效性,并在1.5 kW两电平逆变器中检验所提信号调制电路的动态运行特性。 展开更多
关键词 siC MOSFET si IGBT 混合开关 开关损耗 信号调制
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基于SiC导通比例与开关频率协同调控的Si/SiC混合器件综合热管理方法 被引量:1
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作者 韩硕 涂春鸣 +3 位作者 龙柳 肖凡 肖标 郭祺 《中国电机工程学报》 北大核心 2025年第13期5241-5254,I0026,共15页
SiC MOSFET和Si IGBT并联构成的Si/SiC混合器件(Si/SiC HyS)有效结合了Si IGBT的大载流能力、低成本与SiC MOSFET的高频、低开关损耗优势,突破了单一器件的性能桎梏。然而,非平稳工况下Si/SiC HyS内部结温波动分布不均衡,存在SiC MOSFE... SiC MOSFET和Si IGBT并联构成的Si/SiC混合器件(Si/SiC HyS)有效结合了Si IGBT的大载流能力、低成本与SiC MOSFET的高频、低开关损耗优势,突破了单一器件的性能桎梏。然而,非平稳工况下Si/SiC HyS内部结温波动分布不均衡,存在SiC MOSFET老化过速的问题。目前,针对Si/SiC HyS的热管理策略研究鲜有报道,而变开关频率作为单一器件中应用最为广泛的结温调节方法,难以调节Si/SiC HyS内部的结温差异,导致Si IGBT热容量利用率较低。考虑到SiC导通比例可利用Si IGBT的结温调节空间来降低SiC MOSFET的热应力,从多层级热管理视角出发,提出一种基于SiC导通比例DSiC与开关频率f协同调控的Si/SiC HyS综合热管理方法。所提热管理方法根据设定的结温波动阈值,对开关频率和SiC导通比例的目标参数域进行全面刻画,并实现f-DSiC参数的最短调节路径规划,最终将SiC MOSFET和Si IGBT结温波动平滑至同一阈值以内。实验结果表明,相较于变开关频率方法,采用所提综合热管理方法的Si/SiC HyS最大结温波动降低了24.31%,且任一负载波动下SiC MOSFET和Si IGBT的结温波动均被平滑至同一阈值以内,显著提高了Si/SiC HyS的整体使用寿命。 展开更多
关键词 si/siC混合器件 热管理方法 开关频率 siC导通比例 结温波动
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Carbonated water erosion characteristics and mechanism of tunnel lining cement-based materials in karst environment
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作者 ZOU Min LIU Juan-hong LI Kang 《Journal of Central South University》 2025年第8期3015-3034,共20页
The study aims to investigate the carbonated water erosion mechanism of lining concrete in tunnels traversing karst environment and enhance its resistance.In this study,dynamic carbonated water erosion was simulated t... The study aims to investigate the carbonated water erosion mechanism of lining concrete in tunnels traversing karst environment and enhance its resistance.In this study,dynamic carbonated water erosion was simulated to assess erosion depth,microstructure,phase migrations,and pore structure in various tunnel lining cement-based materials.Additionally,Ca^(2+)leaching was analyzed,and impact of Ca/Si molar ratio in hydration products on erosion resistance was discussed by thermodynamic calculations.The results indicate that carbonated water erosion caused rough and porous surface on specimens,with reduced portlandite and CaCO_(3) content,increased porosity,and an enlargement of pore size.The thermodynamic calculations indicate that the erosion is spontaneous,driven by physical dissolution and chemical reactions dominated by Gibbs free energy.And the erosion reactions proceed more spontaneously and extensively when Ca/Si molar ratio in hydration products was higher.Therefore,cement-based materials with higher portlandite content exhibit weaker erosion resistance.Model-building concrete,with C-S-H gel and portlandite as primary hydration products,has greater erosion susceptibility than shotcrete with ettringite as main hydration product.Moreover,adding silicon-rich mineral admixtures can enhance the erosion resistance.This research offers theory and tech insights to boost cement-based material resistance against carbonated water erosion in karst tunnel engineering. 展开更多
关键词 tunnel lining cement-based materials carbonated water erosion phase analysis pore structure Ca/si molar ratio
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生物基改性纳米P-N-Si协效阻燃聚氨酯泡沫的制备与研究 被引量:1
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作者 蔡军 陈鑫宇 +4 位作者 谷晓昱 孙军 李洪飞 张胜 范瑞兰 《塑料科技》 北大核心 2025年第1期61-67,共7页
硬质聚氨酯泡沫(PU)是一种主链含有大量氨基甲酸酯基(—NHCOO—)重复结构单元的有机高分子材料,遇火极易被点燃。为改善其燃烧性能,研究以m-SiO_(2)为硅源,植酸(PA)为酸源,4-氨基吡啶(4-AP)为氮源,同时选用过渡金属离子Zn^(2+)为催化成... 硬质聚氨酯泡沫(PU)是一种主链含有大量氨基甲酸酯基(—NHCOO—)重复结构单元的有机高分子材料,遇火极易被点燃。为改善其燃烧性能,研究以m-SiO_(2)为硅源,植酸(PA)为酸源,4-氨基吡啶(4-AP)为氮源,同时选用过渡金属离子Zn^(2+)为催化成炭剂,采用逐层改性的方式制备生物基改性P-N-Si系阻燃剂m-SKAPA-Zn。按照质量分数5%、10%、15%的比例添加到PU中,制备阻燃PU复合材料。结果表明:随着m-SKAPA-Zn添加量的增加,阻燃性能整体呈上升趋势,添加质量分数15%m-SKAPA-Zn的PU材料,极限氧指数(LOI)提高至22.6%,UL-94测试可达V-1级,烟密度等级降低37.5%。m-SKAPA-Zn表现出较好的阻燃性和抑烟效果。 展开更多
关键词 硬质聚氨酯泡沫 介孔纳米二氧化硅(m-siO_(2)) 植酸(PA) P-N-si阻燃剂
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Effect of Mg/Si mass ratio on microstructure and mechanical properties of Al-Mg-Si cast aluminum alloy
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作者 Jia-yan Chen Ce Zheng +5 位作者 Cheng Zhu Ying-ju Li Tian-jiao Luo Cui-rong Liu Shao-qiang Xu Yuan-sheng Yang 《China Foundry》 2025年第2期163-172,共10页
The effect of Mg/Si mass ratio on the microstructure and mechanical properties of Al-Mg-Si cast aluminum alloys under sub-rapid solidification conditions was investigated.This study utilized four different Mg/Si ratio... The effect of Mg/Si mass ratio on the microstructure and mechanical properties of Al-Mg-Si cast aluminum alloys under sub-rapid solidification conditions was investigated.This study utilized four different Mg/Si ratios:2.83,1.91,1.73,and 1.53.To analyze the evolution of the microstructure,particularly the second phase,various techniques were employed:optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and electron backscatter diffraction(EBSD).Additionally,thermodynamic calculations were performed using the Thermal-calc software to further understand the microstructural changes.Results show that as the Mg/Si ratio decreases from 2.83 to 1.53,α-Al grains become more uniformly distributed.Meanwhile,the morphology of the Mg_(2)Si phases changes from skeletal to short stick shapes with a decreasing aspect ratio.An as-cast Al-Mg-Si alloy with a Mg/Si ratio of 1.53 exhibits high strength,achieving an ultimate tensile strength(UTS)of 320.6 MPa and a yield strength(YS)of 249.9 MPa.The cast alloy with a Mg/Si ratio of 2.83exhibits the highest elongation,reaching 5.31%.This superior elongation is attributed to the uniform distribution of Mg_(2)Si phases,which possess a long skeletal shape.Conversely,the alloy with a Mg/Si ratio of 1.53 demonstrates the lowest elongation,primarily due to the central concentration of Mg_(2)Si phases,which are characterized by their short stick shapes. 展开更多
关键词 Al-Mg-si casting alloys Mg/si mass ratio dendrite arm spacing Mg_2si phase mechanical properties
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Si元素对钛/钢异种金属接头成形及微观组织影响 被引量:1
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作者 孙清洁 陶玉洁 +3 位作者 甄祖阳 刘一搏 张清华 刘岳 《焊接学报》 北大核心 2025年第1期1-7,共7页
采用T2Cu和CuSi3焊丝在相同工艺参数下对厚度为1 mm的TC4钛合金及304不锈钢进行焊接,并借助光学显微镜(optical microscopy,OM)和扫描电镜(scanning electron microscopy,SEM)研究了两种焊丝下的TC4/304异种金属焊接熔池冶金行为.对比... 采用T2Cu和CuSi3焊丝在相同工艺参数下对厚度为1 mm的TC4钛合金及304不锈钢进行焊接,并借助光学显微镜(optical microscopy,OM)和扫描电镜(scanning electron microscopy,SEM)研究了两种焊丝下的TC4/304异种金属焊接熔池冶金行为.对比分析了不同焊丝成分,尤其是Si元素的加入对TC4/304异种金属接头宏观成形、界面微观组织和力学性能的影响.结果表明,Si元素的加入使液态熔池流动性显著增强,消除了凹陷和孔洞等缺陷,解决了焊缝背部熔合不良问题,焊缝宏观成形显著改善.两种焊丝均有效阻隔了Ti,Fe原子,钛/铜界面未生成Ti-Fe化合物,但在焊缝中心以及铜/钢界面处生成了少量Ti-Fe相.CuSi3焊丝中充足的Si元素不仅使Ti5Si3相形核生长的更加充分,在熔池流动的作用下均匀分布于焊缝中,对接头起到弥散强化作用.与T2Cu焊丝相比,CuSi3焊丝所得接头的抗拉强度提升了81.4%,最高达到366.8 MPa. 展开更多
关键词 钛/钢异种金属焊接 si元素 焊缝成形 微观结构 弥散强化
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Preparation of Silicon Fertilizer Using Lithium Pyroxene Acid-leaching Residues as Starting Materials
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作者 CHEN Jianghua LUO Dawei +2 位作者 GAO Zijie RONG Ke DENG Jiabao 《Journal of Wuhan University of Technology(Materials Science)》 2025年第2期389-399,共11页
We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,ca... We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,calcination temperature of 900℃and calcination time of 120 min were identified as the optimal conditions to maximize the available Si content of the prepared Si fertilizer.The performance of the resulting product satisfies the Chinese agricultural standard for silica fertilizers,providing a new solution for the large-scale harmless and sustainable reuse of lithium pyroxene tailings.The X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)characterization elucidated the formation mechanism of silica fertilizers,and identified KAlSiO_(4)and K_(4)CaSi_(3)O_(9)as the primary silicates products.Observation of the surface morphology of the samples was conducted by scanning electron microscopy(SEM)and X-ray energy dispersive spectrometry(EDS),and compositional analysis of the micro-regions.The acceleration action of CaCO_(3)in the decomposition process of lithium pyroxene acid-leaching residues was demonstrated by the thermogravimetry-differential scanning calorimetry(TG-DSC)test.Determination of heavy metal elements in Si fertilizer was performed by ICP-OES.Potting experiments confirmed that the best growth of pakchoi was achieved when 5 g·kg^(-1)of Si fertilizer was applied.These evidence suggests that the Si fertilizer prepared in this study is a promising candidate for a silica-supplemented soil. 展开更多
关键词 lithium pyroxene acid-leaching residues available silicon calcination method si fertilizer
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Significant Influence on Residual Bending Strength by Cracks Generation During Grinding of Ceramics
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作者 Jinshuo Zhang Tianyi Sui +3 位作者 Bin Lin Bingrui Lv Jingming Li Jingguo Zhou 《Chinese Journal of Mechanical Engineering》 2025年第2期60-83,共24页
Any product must undergo precise manufacturing before use.The damage incurred during the manufacturing process can significantly impact the residual strength of the product post-manufacturing.However,the relationship ... Any product must undergo precise manufacturing before use.The damage incurred during the manufacturing process can significantly impact the residual strength of the product post-manufacturing.However,the relationship between residual bending strength and manufacturing-induced damage remains unclear,despite being a crucial parameter for assessing material service life and performance,leading to a decrease in product performance reliability.This study focuses on investigating the impact of crack generation on residual bending strength through theoretical and experimental analyses of scratching,grinding,and three-point bending.The research first elucidates the forms and mechanisms of material damage through scratch experiments.Subsequently,using resin-bonded and electroplated wheels as case studies,the influence of different process parameters on grinding damage and residual bending strength is explored.The reduction of brittle removal can lead to a 50%–60%decrease in residual bending strength.Lastly,a model is developed to delineate the relationship between processing parameters and the residual bending strength of the product,with the model exhibiting an error margin of less than 11%.This model clearly reveals the effect of crack generation under different process parameters on residual flexural strength. 展开更多
关键词 Hot isostatic pressing sinter si3N4 SCRATCHING GRINDING Residual bending strength
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Preparation and performance characterization of Al_(2)O_(3)–C refractories with in-situ synthesis of β-Sialon
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作者 Chao-fan Yin Jun-rui Yang +5 位作者 Jian-jun Chen Li Wang Bin-bin Dong Xiang-cheng Li Hong-yu Bai Fan Bai 《Journal of Iron and Steel Research International》 2025年第10期3370-3380,共11页
β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy ... β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy on the in-situ synthesis of β-Sialon within Al_(2)O_(3)-C refractory materials,as well as its oxidation behavior,was investigated.The findings indicate that the presence of Al/Si alloy promotes the formation of AlN and SiC whiskers at 1300℃,which subsequently facilitate the production of plate-like β-Sialon at 1500℃.Density functional theory analysis reveals that the(020)crystal plane of β-Sialon exhibits the lowest adsorption energy for Al2O and AlO molecules under the influence of iron atoms,suggesting a solid-liquid-vapor growth mechanism for β-Sialon formation.The introduction of these ceramic phases significantly enhances the mechanical properties of Al_(2)O_(3)-C refractories.Specifically,the addition of 6 wt.%Al/Si alloy yielded specimens with the highest cold modulus of rupture and cold crushing strength at 1500℃,achieving values of 35.2 and 127.5 MPa,respectively--representing increases of 40.1%and 37.4%.Furthermore,during high-temperature oxidation,the formation of plate-like β-Sialon leads to the development of a dense protective layer on the surface.This impedes the diffusion pathways of oxygen and consequently enhances the oxidation resistance of the refractory. 展开更多
关键词 Al_(2)O_(3)-C refractory Al/si alloy Β-siALON Density functional theory Oxidation behavior
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钪和镁复合合金化对Al-10Mg_(2)Si合金组织与力学性能的影响
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作者 赵英 程婷 +3 位作者 秦纪康 伍复发 张莉 武晓峰 《中国稀土学报》 北大核心 2025年第3期595-602,共8页
利用光学显微镜、扫描电镜、X射线衍射仪、室温拉伸试验机等研究了Sc和Mg复合合金化对Al-10Mg_(2)Si合金显微组织、拉伸性能和断裂行为的影响。结果表明,在Al-10Mg_(2)Si合金中添加0.25%Sc能够使初生α-Al晶体的形貌由粗树枝状转变为近... 利用光学显微镜、扫描电镜、X射线衍射仪、室温拉伸试验机等研究了Sc和Mg复合合金化对Al-10Mg_(2)Si合金显微组织、拉伸性能和断裂行为的影响。结果表明,在Al-10Mg_(2)Si合金中添加0.25%Sc能够使初生α-Al晶体的形貌由粗树枝状转变为近球状,同时其晶粒尺寸大大减小;在进一步添加2.8%Mg后,初生α-Al晶粒变得更细、更均匀。另外,0.25%Sc和2.8%Mg的共同添加明显细化了合金中共晶Mg_(2)Si相晶体的尺寸,并且其形貌也由粗大的汉字状转变为细条状、颗粒状或点状。Sc和Mg对α-Al和共晶Mg_(2)Si相的细化、变质作用使得合金的拉伸性能得以大幅提高。共同添加0.25%Sc和2.8%Mg合金的拉伸性能最好,其值分别为345 MPa,145 MPa和8.6%,比未添加合金分别提高48%,41%和231%。 展开更多
关键词 Al-Mg_(2)si合金 Sc和Mg复合合金化 共晶Mg_(2)si 初生Α-AL 拉伸性能
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基于驱动电压主动切换的Si/SiC混合器件结温波动平滑控制
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作者 白丹 涂春鸣 +2 位作者 龙柳 肖凡 肖标 《电工技术学报》 北大核心 2025年第16期5068-5080,共13页
Si/SiC混合器件兼具低成本、低损耗等优势,是支撑电力电子装备大容量、高可靠发展的重要器件。而负载电流变化引起的SiC MOSFET大幅结温波动,制约了Si/SiC混合器件整体寿命的提高。为解决该问题,该文详细分析驱动电压对混合器件开关轨... Si/SiC混合器件兼具低成本、低损耗等优势,是支撑电力电子装备大容量、高可靠发展的重要器件。而负载电流变化引起的SiC MOSFET大幅结温波动,制约了Si/SiC混合器件整体寿命的提高。为解决该问题,该文详细分析驱动电压对混合器件开关轨迹及损耗的影响,提出一种考虑驱动电压主动切换的Si/SiC混合器件结温波动平滑控制策略。所提策略通过在低电流负载区间采用SiC MOSFET损耗较高的驱动电压模式来补偿损耗,高负载电流区间则采用SiC MOSFET损耗较低的驱动电压模式来降低损耗,可以显著平滑Si/SiC混合器件中SiC MOSFET的结温波动,降低其与Si IGBT的结温波动差值,有效延长Si/SiC混合器件整体的剩余使用寿命。实验结果表明,任何负载波动下,该文所提驱动电压主动切换策略均可以将SiC MOSFET的结温波动平滑30%以上,同时SiC MOSFET与Si IGBT的结温波动幅值差减小84.4%。 展开更多
关键词 si/siC混合器件 siC MOSFET 结温波动平滑 驱动电压模式 负载波动
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脉冲磁场频率对Al-7Si-0.55Mg-0.1Ce合金组织演变的影响
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作者 冯艳飞 麻永林 +3 位作者 李岩 鲍鑫宇 刘永珍 邢淑清 《兵器材料科学与工程》 北大核心 2025年第6期91-96,共6页
在Al-7Si-0.55Mg-0.1Ce合金凝固过程施加脉冲磁场处理,分析脉冲磁场对合金凝固组织、晶体结构及硬度的影响。结果表明:在脉冲磁场作用下,随着电流频率增加,合金组织细化效果先减弱后增强。在电流频率为20 Hz时晶粒细化效果最佳,凝固组... 在Al-7Si-0.55Mg-0.1Ce合金凝固过程施加脉冲磁场处理,分析脉冲磁场对合金凝固组织、晶体结构及硬度的影响。结果表明:在脉冲磁场作用下,随着电流频率增加,合金组织细化效果先减弱后增强。在电流频率为20 Hz时晶粒细化效果最佳,凝固组织平均晶粒尺寸为118.3μm,与未处理的试样相比凝固组织平均晶粒尺寸减小14.6%,硬度提高了12.6%。共晶Si形貌也由原来的板条状变为细小的针状或短棒状。脉冲磁场促进了Al原子在<111>、<200>、<220>和<222>方向择优取向堆积。有利于合金凝固组织α-Al晶粒细化、提高硬度和改变共晶Si形貌,为脉冲磁场和稀土Ce复合作用下的合金凝固组织控制提供了新途径。 展开更多
关键词 脉冲磁场 Al-7si-0.55Mg-0.1Ce合金 共晶si 晶粒细化
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