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Recension of boron nitride phase diagram based on high-pressure and high-temperature experiments
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作者 Ruike Zhang Ruiang Guo +3 位作者 Qian Li Shuaiqi Li Haidong Long Duanwei He 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期450-457,共8页
Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride.They can interconvert under varying pressure and temperature conditions.However,this transformation requi... Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride.They can interconvert under varying pressure and temperature conditions.However,this transformation requires overcoming significant potential barriers in dynamics,which poses great difficulty in determining the c-BN/h-BN phase boundary.This study used high-pressure in situ differential thermal measurements to ascertain the temperature of h-BN/c-BN conversion within the commonly used pressure range(3-6 GPa)for the industrial synthesis of c-BN to constrain the P-T phase boundary of h-BN/c-BN in the pressure-temperature range as much as possible.Based on the analysis of the experimental data,it is determined that the relationship between pressure and temperature conforms to the following equation:P=a+1/bT.Here,P denotes the pressure(GPa)and T is the temperature(K).The coefficients are a=-3.8±0.8 GPa and b=229.8±17.1 GPa/K.These findings call into question existing high-pressure and high-temperature phase diagrams of boron nitride,which seem to overstate the phase boundary temperature between c-BN and h-BN.The BN phase diagram obtained from this study can provide critical temperature and pressure condition guidance for the industrial synthesis of c-BN,thus optimizing synthesis efficiency and product performance. 展开更多
关键词 hexagonal boron nitride phase diagram high temperature and high pressure cubic boron nitride phase transition differential thermal analysis
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High Nitrogen Austenitic Stainless Steels Manufactured by Nitrogen Gas Alloying and Adding Nitrided Ferroalloys 被引量:15
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作者 LI Hua-bing JIANG Zhou-hua SHEN Ming-hui YOU Xiang-mi 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第3期63-68,共6页
A simple and feasible method for the production of high nitrogen austenitic stainless steels involves nitrogen gas alloying and adding nitrided ferroalloys under normal atmospheric conditions. Alloying by nitrogen gas... A simple and feasible method for the production of high nitrogen austenitic stainless steels involves nitrogen gas alloying and adding nitrided ferroalloys under normal atmospheric conditions. Alloying by nitrogen gas bubbling in Fe-Cr-Mn-Mo series alloys was carried out in MoSi2 resistance furnace and air induction furnace under normal atmospheric conditions. The results showed that nitrogen alloying could be accelerated by increasing nitrogen gas flow rate, prolonging residence time of bubbles, increasing gas/molten steel interfaces, and decreasing the sulphur and oxygen contents in molten steel. Nitrogen content of 0.69% in 18Crl8Mn was obtained using air induction furnace by bubbling of nitrogen gas from porous plug. In addition, the nickel-free, high nitrogen austenitic stainless steels with sound and compact macrostructure had been produced in the laboratory using vacuum induction furnace and electroslag remelting furnace under nitrogen atmosphere by the addition of nitrided alloy with the maximum nitrogen content of 0.81%. Pores were observed in the ingots obtained by melting and casting in vacuum induction furnace with the addition of nitrided ferroalloys and under nitrogen atmosphere. After electroslag remelting of the cast ingots, they were all sound and were free of pores. The yield of nitrogen increased with the decrease of melting rate in the ESR process. Due to electroslag remelting under nitrogen atmosphere and the consequential addition of aluminum as deoxidizer to the slag, the loss of manganese decreased obviously. There existed mainly irregular Al2O3 inclusions and MnS inclusions in ESR ingots, and the size of most of the inclusions was less than 5 um. After homogenization of the hot rolled plate at 1 150℃ × 1 h followed by water quenching, the microstructure consisted of homogeneous austenite. 展开更多
关键词 nitrogen gas alloying nitrided ferroalloy high nitrogen austenitic stainless steel vacuum induction melting electroslag remelting
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Effect of frequency and pulse-on time of high power impulse magnetron sputtering on deposition rate and morphology of titanium nitride using response surface methodology 被引量:6
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作者 Saeed GHASEMI Ali Reza FARHADIZADEH Hamid GHOMI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第12期2577-2590,共14页
Titanium nitride thin films were deposited on silicon by high power impulse magnetron sputtering(HiPIMS)method at different frequencies(162-637 Hz)and pulse-on time(60-322μs).Response surface methodology(RSM)was empl... Titanium nitride thin films were deposited on silicon by high power impulse magnetron sputtering(HiPIMS)method at different frequencies(162-637 Hz)and pulse-on time(60-322μs).Response surface methodology(RSM)was employed to study the simultaneous effect of frequency and pulse-on time on the current waveforms and the crystallographic orientation,microstructure,and in particular,the deposition rate of titanium nitride at constant time and average power equal to 250 W.The crystallographic structure and morphology of deposited films were analyzed using XRD and FESEM,respectively.It is found that the deposition rate of HiPIMS samples is tremendously dependent on pulse-on time and frequency of pulses where the deposition rate changes from 4.5 to 14.5 nm/min.The regression equations and analyses of variance(ANOVA)reveal that the maximum deposition rate(equal to(17±0.8)nm/min)occurs when the frequency is 537 Hz and pulse-on time is 212μs.The experimental measurement of the deposition rate under this condition gives rise to the deposition rate of 16.7 nm/min that is in good agreement with the predicted value. 展开更多
关键词 high powder impulse magnetron sputtering(HiPIMS) titanium nitride response surface methodology(RSM) deposition rate analyses of variance(ANOVA)
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Thick free-standing electrode based on carbon-carbon nitride microspheres with large mesopores for high-energy-density lithium-sulfur batteries 被引量:2
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作者 Hui-Ju Kang Tae-Gyu Lee +8 位作者 Heejin Kim Jae-Woo Park Hyun Jin Hwang Hyeonseok Hwang Kwang-Suk Jang Hae Jin Kim Yun Suk Huh Won Bin Im Young-Si Jun 《Carbon Energy》 CAS 2021年第3期410-423,共14页
The development of sulfur cathodes with high areal capacity and high energy density is crucial for the practical application of lithium-sulfur batteries(LSBs).LSBs can be built by employing(ultra)high-loading sulfur c... The development of sulfur cathodes with high areal capacity and high energy density is crucial for the practical application of lithium-sulfur batteries(LSBs).LSBs can be built by employing(ultra)high-loading sulfur cathodes,which have rarely been realized due to massive passivation and shuttling.Herein,microspheres of a carbon-carbon nitride composite(C@CN)with large mesopores are fabricated via molecular cooperative assembly.Using the C@CN-based electrodes,the effects of the large mesopores and N-functional groups on the electrochemical behavior of sulfur in LSB cells are thoroughly investigated under ultrahigh sulfur-loading conditions(>15 mgS cm^(-2)).Furthermore,for high-energy-density LSBs,the C@CN powders are pelletized into a thick free-standing electrode(thickness:500^m;diameter:11 mm)via a simple briquette process;here,the total amount of energy stored by the LSB cells is 39 mWh,corresponding to a volumetric energy density of 440 Wh L-1 with an areal capacity of 24.9 and 17.5 mAh cm^(-2) at 0.47 and 4.7 mA cm^(-2),respectively(at 24mgS cm^(-2)).These results have significantly surpassed most recent records due to the synergy among the large mesopores,(poly)sulfide-philic surfaces,and thick electrodes.The developed strategy with its potential for scale-up successfully fills the gap between laboratory-scale cells and practical cells without sacrificing the high areal capacity and high energy density,providing a solid foundation for the development of practical LSBs. 展开更多
关键词 briquette process carbon nitride free-standing electrode high energy density lithium-sulfur batteries MESOPORES
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The Phenomenon of High Hardness Values on the S-Phase Layer of Austenitic Stainless Steel via Screen Plasma Nitriding Process 被引量:2
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作者 Sang-Gweon Kim Kook-Hyun Yeo +2 位作者 Yong-Ki Cho Jae-Hoon Lee Masahiro Okumiya 《Advances in Materials Physics and Chemistry》 2018年第6期257-268,共12页
The purpose of this study is to improve the surface properties of austenitic stainless steel using the double-folded electrode screen plasma nitriding (SPN) process. In general, the S-phase is well-known for its excel... The purpose of this study is to improve the surface properties of austenitic stainless steel using the double-folded electrode screen plasma nitriding (SPN) process. In general, the S-phase is well-known for its excellent properties such as improved hardness and wear resistance along with sustained corrosion resistance. The concentrated nitrogen via SPN process was injected to form S-phase with time at 713 K. This study was carried out under the conditions of 44 at% of nitrogen injection, which was higher than 25 at% known as the condition of no precipitation of S-phase formed by the SPN process, and 20 K higher than the maximum temperature without precipitation phase. The hardness analysis of stainless steel sample treated by the SPN process at 713 K showed a much higher value than the typical nitriding hardness at a depth of lower nitrogen than the maximum nitrogen concentration. The SPN 20 hr treated specimen showed the average value of 2339 HV while 40 hr showed the average value of 2215 HV. The result is attributed to the concentrated nitrogen formed in the SPN process reacting with the alloying elements contained in the base material to form fine precipitates, thus producing a synergy effect of the extreme hardening effect;that is, the movement of precipitates and dislocations due to the GP-zone (Guinier-Preston zone). 展开更多
关键词 Double-Folded Electrode Austenitic Stainless Steel (ASS) SCREEN Plasma nitridING (SPN) PROCESS S-PHASE Corrosion Resistance high Hardness
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Fabrication and residual stresses of aluminum nitride ceramics sintered at high-pressure
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作者 Li Xiaolei~(1,2),Ma Hongan~2,Zang Chuanyi~1,Zheng Youjin~(2,3),Liu Yu~1,Zuo Guihong~3, Li Jigang~1,Li Shangsheng~2,Jia Xiaopeng~(1,2) (1.Henan Polytechnic University,Jiaozuo 454000,China 2.National Lab of Superhard Materials,Jilin University,Changchun 130012,China 3.Mudanjiang Teachers College,Mudanjiang 157012,China) 《金刚石与磨料磨具工程》 CAS 北大核心 2008年第S1期181-185,共5页
High-density AlN ceramics were fabricated without sintering additives at high pressure(5.0 GPa) and temperature(1300~1800℃).The sintered bodies were characterized by XRD,SEM and micro-Raman spectroscopy(MRS).Control... High-density AlN ceramics were fabricated without sintering additives at high pressure(5.0 GPa) and temperature(1300~1800℃).The sintered bodies were characterized by XRD,SEM and micro-Raman spectroscopy(MRS).Controlling fracture mode was intragranular when the sintering temperature was as low as 1400℃under 5.0 GPa.The values of residual stresses due to the distortion of the AlN lattice were assessed using the Micro-Raman Spectroscopy(MRS).The residual compression stress of the AlN ceramics sintered at 5.0 GPaand 1700℃for 125 min is 2.0 GPa.The residual compression stress is increased according to the extension of the sintering time. 展开更多
关键词 aluminium nitridE high pressure SINTERING microstructure RESIDUAL STRESS
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Analysis and Characterization of Normally-Off Gallium Nitride High Electron Mobility Transistors
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作者 Shahzaib Anwar Sardar Muhammad Gulfam +3 位作者 Bilal Muhammad Syed Junaid Nawaz Khursheed Aurangzeb Mohammad Kaleem 《Computers, Materials & Continua》 SCIE EI 2021年第10期1021-1037,共17页
High electron mobility transistor(HEMT)based on gallium nitride(GaN)is one of the most promising candidates for the future generation of high frequencies and high-power electronic applications.This research work aims ... High electron mobility transistor(HEMT)based on gallium nitride(GaN)is one of the most promising candidates for the future generation of high frequencies and high-power electronic applications.This research work aims at designing and characterization of enhancement-mode or normally-off GaN HEMT.The impact of variations in gate length,mole concentration,barrier variations and other important design parameters on the performance of normally-off GaN HEMT is thoroughly investigated.An increase in the gate length causes a decrease in the drain current and transconductance,while an increase in drain current and transconductance can be achieved by increasing the concentration of aluminium(Al).For Al mole fractions of 23%,25%,and 27%,within Al gallium nitride(AlGaN)barrier,the GaN HEMT devices provide a maximum drain current of 347,408 and 474 mA/μm and a transconductance of 19,20.2,21.5 mS/μm,respectively.Whereas,for Al mole fraction of 10%and 15%,within AlGaN buffer,these devices are observed to provide a drain current of 329 and 283 mA/μm,respectively.Furthermore,for a gate length of 2.4,3.4,and 4.4μm,the device is observed to exhibit a maximum drain current of 272,235,and 221 mA/μm and the transconductance of 16.2,14,and 12.3 mS/μm,respectively.It is established that a maximum drain current of 997 mA/μm can be achieved with an Al concentration of 23%,and the device exhibits a steady drain current with enhanced transconductance.These observations demonstrate tremendous potential for two-dimensional electron gas(2DEG)for securing of the normally-off mode operation.A suitable setting of gate length and other design parameters is critical in preserving the normally-off mode operation while also enhancing the critical performance parameters at the same time.Due to the normallyon depletion-mode nature of GaN HEMT,it is usually not considered as suitable for high power levels,frequencies,and temperature.In such settings,a negative bias is required to enter the blocking condition;however,in the before-mentioned normally-off devices,the negative bias can be avoided and the channel can be depleted without applying a negative bias. 展开更多
关键词 high electron mobility GAN HEMT bipolar transistors gallium nitride HETEROJUNCTIONS MOS devices
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The Adhesion Improvement of Cubic Boron Nitride Film on High Speed Steel Substrate Implanted by Boron Element
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作者 CAI Zhi-hai(蔡志海) +3 位作者 ZHANG Ping(张平) TAN Jun(谭俊) 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第4期387-391,396,共6页
Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS a... Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS and AFM. The experimental results show that the implantation of boron atom can reduce the internal stress and improve the adhesion strength of the films. The critical load of scratch test rises to 27.45 N, compared to 1.75 N of c-BN film on the unimplanted HSS. The AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. Then the composition of the boron implanted layer was analyzed by the XPS. And the influence of the boron implanted layer on the internal stress and adhesion strength of c-BN films were investigated. 展开更多
关键词 cubic boron nitride film high speed steel(HSS) ion implantation internal stress ADHESION
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High-Throughput Growth of Hexagonal Boron Nitride Film Using Porous-Structure Isolation Layer
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作者 Ruitao Jia Fangzhu Qing Xuesong Li 《Journal of Materials Science and Chemical Engineering》 CAS 2023年第3期45-51,共7页
Chemical vapor deposition is considered as the most hopeful method for the synthesis of large-area high-quality hexagonal boron nitride on the substrate of catalytic metal. However, the size the hexagonal boron nitrid... Chemical vapor deposition is considered as the most hopeful method for the synthesis of large-area high-quality hexagonal boron nitride on the substrate of catalytic metal. However, the size the hexagonal boron nitride films are limited to the size of growth chamber, which indicates a lower production efficiency. In this paper, the utilization efficiency of growth chamber is highly improved by alternately stacking multiple pieces of Cu foils and carbon fiber surface felt with porous structure. Uniform and continuous hexagonal boron nitride films are prepared on Cu foils through chemical vapor deposition utilizing ammonia borane as the precursor. This work develops a simple and practicable method for high-throughput preparation of hexagonal boron nitride films, which could contribute to the industrial application of hexagonal boron nitride. . 展开更多
关键词 Hexagonal Boron nitride Chemical Vapor Deposition Porous Structure Isolation Layer high Throughput
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Aluminum Nitride for High Brightness LED Packaging Applications
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作者 Jonathan Harris Li Xin-yu 《真空电子技术》 2015年第5期1-5 29,29,共6页
Aluminum Nitride(ALN)is a high thermal conductivity material which is being used with increasing frequency in packaging applications for high brightness LEDs(HBLED).This paper introduce Aluminum Nitride substrate fabr... Aluminum Nitride(ALN)is a high thermal conductivity material which is being used with increasing frequency in packaging applications for high brightness LEDs(HBLED).This paper introduce Aluminum Nitride substrate fabrication process and different ALN metallization approaches.It is clear that the most technically appropriate metallization approach for HBLED packging is DPC.This paper explain why the cost of ALN substrate is so high and give the future of ALN in HBLED applications. 展开更多
关键词 ALUMINUM nitridE high BRIGHTNESS LIGHT EMITTING DI
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New Type of Nitrides with High Electrical and Thermal Conductivities
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作者 Ning Liu Xiaolong Chen +2 位作者 Jiangang GUO Jun Deng Liwei Guo 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第8期70-73,共4页
The nitrogen dimer as both a fundamental building unit in designing a new type of nitrides, and a material gene associated with high electrical and thermal conductivities is investigated by first principles calculatio... The nitrogen dimer as both a fundamental building unit in designing a new type of nitrides, and a material gene associated with high electrical and thermal conductivities is investigated by first principles calculations.The results indicate that the predicted Si N4 is structurally stable and reasonably energy-favored with a striking feature in its band structure that exhibits free electron-like energy dispersions. It possesses a high electrical conductivity(5.07 × 10^5 S/cm) and a high thermal conductivity(371 W/m·K) comparable to copper. The validity is tested by isostructural Al N4 and Si C4. It is demonstrated that the nitrogen dimers can supply a high density of delocalized electrons in this new type of nitrides. 展开更多
关键词 Si New Type of nitrides with high Electrical and Thermal Conductivities
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High Resolution Electron Microscopy Observations of Structural Changes in Iron Nitride Films Annealed in Vacuum
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作者 Shengkai GONG Huibin XU (Dept. of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1997年第2期123-126,共4页
Iron-nitride films were prepared by reactive sputtering, and the effect of annealing treatment on the structures was investigated by means of in-situ electron microscopy and high resolution electron microscopy (HREM).... Iron-nitride films were prepared by reactive sputtering, and the effect of annealing treatment on the structures was investigated by means of in-situ electron microscopy and high resolution electron microscopy (HREM). As-deposited films were observed to be a mixed structure of a few ultrafine epsilon-Fe2-3N particles existing in the amorphous matrix. it was found that the structure-relaxation in the amorphous occurred at 473 K, and the ultrafine grains began to grow at the higher annealing temperatures. The transition of the amorphous to epsilon-Fe2-3N was almost completed at 673 K. It is considered that the formation of the ideal epsilon-Fe3N is originated from the ordering of the nitrogen atoms during the annealing in vacuum. On the other hand, gamma'-phase (Fe4N) was seen to precipitation of epsilon-phase at 723 K. Two possible modes are proposed in the precipitation of gamma'-phase, depending on the heating rate and crystallographic orientation relationships, i.e. [121](epsilon)//[001](gamma), (2(1) over bar0$)(epsilon)//(110)(gamma) and [100](epsilon)//[110](gamma), (001)(epsilon)//(111)(gamma). In addition, alpha-Fe particles were observed to form from the gamma'-phase at high temperatures. We assumed that these structural changes are due to the diffusion of nitrogen and iron atoms during the annealing, except for the case of the precipitation of the gamma'-phase as depicted above. The results obtained in this work are in a good agreement with the assumption. 展开更多
关键词 FIGURE high Resolution Electron Microscopy Observations of Structural Changes in Iron nitride Films Annealed in Vacuum
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Preparation of silicon carbide nitride films on Si substrate by pulsed high-energy density plasma
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作者 Xueming Li Size Yang Xingfang Wu 《Journal of University of Science and Technology Beijing》 CSCD 2006年第3期272-276,共5页
Thin films of silicon carbide nitride (SiCN) were prepared on (111) oriented silicon substrates by pulsed high-energy density plasma (PHEDP). The evolution of the chemical bonding states between silicon, nitroge... Thin films of silicon carbide nitride (SiCN) were prepared on (111) oriented silicon substrates by pulsed high-energy density plasma (PHEDP). The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C 1s and N 1s spectra shift to lower binding energy due to the formation of C--Si and N--Si bonds. The Si--C--N bonds were observed in the deconvolved C ls and N ls spectra. The X-ray diffractometer (XRD) results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy (SEM). 展开更多
关键词 silicon carbide nitride pulsed high-energy density plasma chemical bonding state
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Improvement of the Corrosion Resistance of High Alloyed Austenitic Cr-Ni-Mo Stainless Steels by Solution Nitriding
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作者 Christine Eckstein Heinz- Joachim Spies Jochen Albrecht 《材料热处理学报》 EI CAS CSCD 北大核心 2004年第5期316-321,共6页
Characteristic features of austenitic steel grades combine a good corrosion resistance with a low hardness, wear resistance and scratch resistance. An interesting possibility for improving the wear behaviour of these ... Characteristic features of austenitic steel grades combine a good corrosion resistance with a low hardness, wear resistance and scratch resistance. An interesting possibility for improving the wear behaviour of these steels without loss of their corrosion resistance lies in enriching the near surface region with nitrogen. The process of a solution nitriding allows the rise of the solution of nitrogen in the solid phase. On this state nitrogen increases the corrosion resistance and the tribilogical load-bearing capacity. The aim of the study was, to investigate the improvement of the pitting corrosion behaviour by solution nitriding. A special topic was to observe the effect of nitrogen by different molybdenum content. So austenitic stainless steels (18% Cr, 12% Ni, Mo gradation between 0.06 to 3.6%) had been solution nitrided. The samples could be prepared with various surface content of nitrogen from 0.04 to 0.45% with a step-by-step grinding. The susceptibility against pitting corrosion of these samples had been tested by determination of the stable pitting potential in 0.5M and 1M NaCl at 25°C. For the investigated steel composition and the used corrosion system there is no influence of molybdenum on the effectiveness of nitrogen. The influence of nitrogen to all of the determined parameters can be described well by PRE = Cr + 3,3 * Mo + 25 *N. XPS analysis of the sample surfaces support the results of the pitting corrosion tests.Additionally surface investigations with an acid elektolyte (0,1M HC1 + 0,4M NaCl) were performed. In this case the passivation effective nitrogen content increases markedly with rising molybdenum concentration of the steel. Obviously an interaction of Mo and N is connected with a strongly acid electrolyte. 展开更多
关键词 耐蚀性 奥氏体不锈钢 CR-NI-MO 渗氮 PRE 稳定点蚀电位
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Research Progress of Non-oxide and High Entropy Ceramic Coatings
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作者 Junshuai CHEN Yulong WANG +5 位作者 Zeyu WANG Xue SHEN TengyuDU Yubo GONG Zhigang YANG Gang YU 《Research and Application of Materials Science》 2024年第1期23-32,共10页
Ceramic coatings play a keyrole in extending the service life of materials in aerospaceandenergy fields byprotectingmaterials from high temperature,oxidation,corrosion and thermal stress.Non-oxide and high entropy cer... Ceramic coatings play a keyrole in extending the service life of materials in aerospaceandenergy fields byprotectingmaterials from high temperature,oxidation,corrosion and thermal stress.Non-oxide and high entropy ceramics are new emerging coating materials which have been researched and developed in recent years.Compared with traditional oxide ceramics,non-oxide ceramics have better high temperature stability,oxidation resistance and erosion resistance.These characteristics make non-oxide ceramics perform well in extreme environments.It is particularly noteworthy that the non-oxide high entropy ceramic is a uniform solid solution composed of at least four or fiveatoms.Their unique structure and outstanding propertiesshow great potential application in the field of coating.In this paper,the researches aboutregulating microstructure,preparation technology and properties of nitride and its high entropy system,carbide and its high entropy system and boride and its high entropy system in coating field are summarized,and their future development and prospects are prospected. 展开更多
关键词 nitridE CARBIDE BORIDE high entropy ceramic coating
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Applications of Wide Bandgap Semiconductor Materials in High-Power Electronic Devices
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作者 Yucheng Zhou 《World Journal of Engineering and Technology》 2024年第4期1034-1045,共12页
Wide bandgap semiconductor materials are driving revolutionary improvements in the performance of high-power electronic devices. This study systematically evaluates the application prospects of wide bandgap semiconduc... Wide bandgap semiconductor materials are driving revolutionary improvements in the performance of high-power electronic devices. This study systematically evaluates the application prospects of wide bandgap semiconductor materials in high-power electronic devices. The research first compares the physical properties of major wide bandgap materials (such as silicon carbide SiC and gallium nitride GaN), analyzing their advantages over traditional silicon materials. Through theoretical calculations and experimental data analysis, the study assesses the performance of these materials in terms of high breakdown field, high thermal conductivity, and high electron saturation velocity. The research focuses on the application of SiC and GaN devices in power electronics, including high-voltage DC transmission, electric vehicle drive systems, and renewable energy conversion. The study also discusses the potential of wide bandgap materials in RF and microwave applications. However, the research also points out the challenges faced by wide bandgap semiconductor technology, such as material defect control, device reliability, and cost issues. To address these challenges, the study proposes solutions, including improving epitaxial growth techniques, optimizing device structure design, and developing new packaging methods. Finally, the research looks ahead to the prospects of wide bandgap semiconductors in emerging application areas such as quantum computing and terahertz communications. This study provides a comprehensive theoretical foundation and technology roadmap for the application of wide bandgap semiconductor materials in high-power electronic devices, contributing to the development of next-generation high-efficiency energy conversion and management systems. 展开更多
关键词 Wide Bandgap Semiconductors high-Power Electronics Silicon Carbide Gallium nitride Power Electronics
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High Performance 70nm CMOS Devices
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作者 徐秋霞 钱鹤 +5 位作者 殷华湘 贾林 季红浩 陈宝钦 朱亚江 刘明 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第2期134-139,共6页
A high performance 70nm CMOS device has been demonstrated for the first time in the continent, China. Some innovations in techniques are applied to restrain the short channel effect and improve the driving ability, ... A high performance 70nm CMOS device has been demonstrated for the first time in the continent, China. Some innovations in techniques are applied to restrain the short channel effect and improve the driving ability, such as 3nm nitrided oxide, dual poly Si gate electrode, novel super steep retrograde channel doping by heavy ion implantation, ultra shallow S/D extension formed by Ge PAI(Pre Amorphism Implantation) plus LEI(Low Energy Implantation), thin and low resistance Ti SALICIDE by Ge PAI and special cleaning, etc. The shortest channel length of the CMOS device is 70nm. The threshold voltages, G m and off current are 0 28V,490mS·mm -1 and 0 08nA/μm for NMOS and -0 3V,340mS·mm -1 and 0 2nA/μm for PMOS, respectively. Delays of 23 5ps/stage at 1 5V, 17 5ps/stage at 2 0V and 12 5ps/stage at 3V are achieved in the 57 stage unloaded 100nm CMOS ring oscillator circuits. 展开更多
关键词 high performance 70nm CMOS device S/D extension nitrided gate oxide Ge PAI SALICIDE
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Electrical Properties of Ultra Thin Nitride/Oxynitride Stack Dielectrics pMOS Capacitor with Refractory Metal Gate
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作者 钟兴华 吴峻峰 +1 位作者 杨建军 徐秋霞 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第4期651-655,共5页
Electrical properties of high quality ultra thin nitride/oxynitride(N/O)stack dielectrics pMOS capacitor with refractory metal gate electrode are investigated,and ultra thin (<2 nm) N/O stack gate dielectrics with ... Electrical properties of high quality ultra thin nitride/oxynitride(N/O)stack dielectrics pMOS capacitor with refractory metal gate electrode are investigated,and ultra thin (<2 nm) N/O stack gate dielectrics with significant low leakage current and high resistance to boron penetration are fabricated.Experiment results show that the stack gate dielectric of nitride/oxynitride combined with improved sputtered tungsten/titanium nitride (W/TiN) gate electrode is one of the candidates for deep sub-micron metal gate CMOS devices. 展开更多
关键词 equivalent oxide thickness nitride/oxynitride gate dielectric stack high k boron-penetration metal gate
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Study of high pressure sintering behavior of CBN composites starting with CBN-Al mixtures 被引量:3
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作者 Li Yongjun Li Sicheng Lv Ran Qin Jiaqian Zhang Jian Wang Jianghua Wang Fulong Kou Zili He Duanwei (Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,China) 《金刚石与磨料磨具工程》 CAS 北大核心 2008年第S1期176-180,190,共6页
Cubic boron nitride(CBN) composites starting with CBN-Al mixtures were sintered on WC-16 wt%Co substrate under static high pressure of 5.0 GPa at temperatures of 800 to 1 400℃for 30 min.Vickers hardness of the sinter... Cubic boron nitride(CBN) composites starting with CBN-Al mixtures were sintered on WC-16 wt%Co substrate under static high pressure of 5.0 GPa at temperatures of 800 to 1 400℃for 30 min.Vickers hardness of the sintered samples increased with increasing CBN content and the highest hardness of 32.7 GPa was achieved for the CBN-5 wt%Al specimens sintered at 1 400℃.The reactions between CBN and Al started to occur at about 900℃and the reaction products strongly depended on the Al content,sintering temperature and Co diffused from the substrates according to the x-ray diffraction(XRD) observations.The CBN composite sintered at 1 200℃from a CBN-15 wt%Al mixture showed the best cutting performance. 展开更多
关键词 CUBIC BORON nitridE high pressure and high temperature sintering
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Electric field modulation technique for high-voltage AlGaN/GaN Schottky barrier diodes 被引量:1
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作者 汤岑 谢刚 +3 位作者 张丽 郭清 汪涛 盛况 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期406-411,共6页
A novel structure of AIGaN/GaN Schottky barrier diode (SBD) featuring electric field optimization techniques of anode-connected-field-plate (AFP) and magnesium-doped p-type buried layer under the two-dimensional e... A novel structure of AIGaN/GaN Schottky barrier diode (SBD) featuring electric field optimization techniques of anode-connected-field-plate (AFP) and magnesium-doped p-type buried layer under the two-dimensional electron gas (2DEG) channel is proposed. In comparison with conventional A1GaN/GaN SBDs, the magnesium-doped p-type buried layer in the proposed structure can provide holes that can help to deplete the surface 2DEG. As a result, surface field strength around the electrode edges is significantly suppressed and the electric field along the channel is distributed more evenly. Through 2D numerical analysis, the AFP parameters (field plate length, LAFP, and field plate height, TAFP) and p-type buried layer parameters (p-type layer concentration, Np, and p-type layer thickness, Tp) are optimized to achieve a three-equal-peak surface channel field distribution under exact charge balance conditions. A novel structure with a total drift region length of 10.5 μm and a magnesium-doped p-type concentration of 1 × 10^17 cm 3 achieves a high breakdown voltage (VB) of 1.8 kV, showing 5 times improvement compared with the conventional SBD with the same device dimension. 展开更多
关键词 gallium nitride high voltage SBD field plate magnesium buried layer
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