共查询到20条相似文献,搜索用时 109 毫秒
1.
Aninvestigationonplasmasprayingwithartificialbonepowderandbondingcharacteristicsofcoating¥TianLi;LiJinglongandLinQiansheng(No... 相似文献
2.
1 INTRODUCTIONGrainrefinementofferssubstantialbenefitsinbothcontinuouscastingbydirectchill (DC)andincast to shapeproducts[1].Al 5%Ti 1 %Bmasteral loy ,whichmainlycontainsTiAl3andTiB2 particlesinAlmatrix[2 ,3]hasbeenproventogivethebestgrainrefinement[4 ,5 ].Additionof 0 … 相似文献
3.
1 INTRODUCTIONPlasmaarcwelding (PAW )ischaracterizedbyeasyoperationandlowcostamongthehigh energy density beam processingtechniques (forexample ,electronbeam ,laserand plasma) .PAWiswidelyusedinweldingofstainlesssteel,high nickelalloys ,carbonsteel,copper ,copper … 相似文献
4.
Effect of high temperature aging on microstructure and mechanical properties of a directionally solidified Ni3Al base alloy IC6A 总被引:2,自引:0,他引:2
1 INTRODUCTIONThedirectionallysolidifiedNi3AlbasealloyIC6AwiththechemicalcompositionofNi (7.5~8.5 )Al (13.0~ 15 .0 )Mo (0 .0 2~ 0 .1)B (0 .0 0 5~0 .0 5 )Y (massfraction ,% )hasbeenrecentlydevel opedbasedonalloyIC6asahigh temperaturestruc turalmaterialusedforadvancedjet enginevanesop er… 相似文献
5.
DeterminationofNi,Ca,Mg,CuandPbinWolframbyInductivelyCoupledPlasmaAtomicEmisionSpectrometryWangChunmeiandZhangShuzhen(王春梅)(张淑... 相似文献
6.
X.L.Zhao) T.L.Guo) M.Ohkohchi) T.Okazaki) S.Iijima Y.Ando) ) Japan Science Technology Corporation Department of Physics Meijo University Shiogamaguchi Tempaku ku Nagoya Japan ) Scientific Research Department Sh 《金属学报(英文版)》1999,12(4):345-352
1.IntroductionMultiwalledcarbonnanotubes(MWNTs)werefoundbyoneofthepresentauthors(S.Iijima)〔1〕insidethecathodedeposits,whichwereobtainedbyanotherauthor(Y.Ando)〔1,2,3〕asbyproductsoffullereneproductionusingaDCarcdischargeevaporationininertgas.TheMWNTsc… 相似文献
7.
1 INTRODUCTIONRecentarc plasmatechnologyhasbeenwidelyusedinmanyfields,suchasroboticwelding ,plasmaspraying ,thermalplasmachemistry , 相似文献
8.
Tribological behavior of different films on Ti-6Al-4V alloy prepared by plasma-based ion implantation 总被引:3,自引:0,他引:3
1 INTRODUCTIONTi 6Al 4Valloyiswidelyusedinaviation ,spaceandmedicalindustriesbutrestrictedtotribologicalapplicationstoacertainextent[1,2 ] .Theuseofanewcost effectivetechnique ,plasma basedionimplanta tion (PBII) ,forimprovingsurface propertiesbyformingTiN ,carbid… 相似文献
9.
LGK系列空气等离子切割机的使用与维修天津大学机电工厂(300072)缪贵宾OperationandRepairofLGKSeriesAirPlasmaCuttingMachine¥(TianjinUniversityMachineryandElec... 相似文献
10.
S.Ogibayashi Chiba Institute of Technology DepartmentofIndustrialand Management Systems Engineering Tsudanu ma Narashino shi Chiba ken Japan 《金属学报(英文版)》1999,12(4):297-303
1IntroductionMathematicalmodelsforcontinuoscastinghavebeendevelopedinvariousaspectssuchasmacroscopicsolidification,flowofmoltensteel,simultaneouscalculationofflowandheatflux,macroscopicdeformationofmoldandstrand,microsegregation,stressandstraininsec… 相似文献
11.
13.
14.
15.
提出了一种用于变极性焊接电源的新型半桥式二次逆变电路拓扑,它由续流耦合电感、IGBT半桥电路及其RC缓冲电路组成.该电路既能确保在极性切换过程中获得快速的焊接电流换向速度,又能够通过硬件电路本身提供足够高的再燃弧电压,用以在焊接电流过零瞬间重新引燃电弧.针对新型半桥式二次逆变电路的特点,研究了开关切换控制策略以及换向电流控制策略.结果表明,电源系统在具有良好的变极性输出性能的同时,还有硬件电路结构简单、成本低、系统效率高等优点,具有很好的产业化应用前景. 相似文献
16.
A digital controlled alternating electromagnetic stirring generator based on dual inverter structure 下载免费PDF全文
A digital controlled alternating electromagnetic stirring generator is proposed in this paper. The main circuit of the generator makes use of dual inverter structure among which the former inverter uses full bridge zero voltage switching topology and the latter inverter uses full bridge inverter circuit. To improve the dynamic response performance, the inverting frequency of the former inverter is as high as 100kHz. The Cortex-M3 kernel based ARM microcontroller LM3S818 is adopted as the cybernetics core of the digital control system to achieve accurate, stable and flexible control of the generator. All the PWM signals for the former and latter inverters are generated by the LM3S818 directly. The constant current characteristic of the former inverter is obtained through current close-loop feedback control, and can ensure the operation safety when the output current waveform is at zero crossing point. Both simulation and experiment results show that the proposed generator is with such advantages as wide soft-switching range, perfect control accuracy and flexible waveform modulation, and can fulfill the requirements of electromagnetic stirring process. 相似文献
17.
18.
针对并联逆变电源设计的难点--起动问题,提出了一种扫频式它激到自激转换的起动电路.电路由鉴相部分和起动部分构成,详细分析了起动过程的相关问题,给出了仿真结果,并研制了一台50 kW样机.实验结果证明,该起动电路从18~38 kHz,均能实现扫频的成功起动,扫频范围高达20 kHz,扫频范围宽,起动成功率可达95%以上. 相似文献
19.
20.
随着高性能薄板合金的广泛应用,基于实时能量控制波形弧焊技术的发展,对弧焊电源动特性提出了更高的要求.通过对移相全桥弧焊逆变电源的分析,可知移相全桥主电路本质上可等效为Buck模型,利用电路理论推导出小信号模型等效电路的电流传递函数,结合弧焊电源具体特点并进行简化,运用自动控制原理知识分析了弧焊逆变电源的动特性影响因素,并对基于峰值电流反馈的斜坡补偿方法进行具体设计分析,得出了基于峰值电流反馈弧焊逆变电源的动特性与输出回路电抗大小无关的结论.结果表明,仿真和实际电路试验结果均表明分析过程的正确性. 相似文献