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1 INTRODUCTIONItiswellknownthattheimportantreasontohindertheapplicationofCu basedmaterialsistheirinferiormechanical properties.ThedispersionstrengtheningCu basedmaterialsproducedbycastingorinner oxidizinghavenowbeen putintopracticalusageinsomedevelopedc… 相似文献
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1 INTRODUCTIONThetwosuccessfulfamiliesofrare earthcobaltpermanentmagnetsproducedcommerciallyareSmCo5andSm2 Co17.TheSmCo5magnetshaveb 相似文献
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1 INTRODUCTIONSulfurdistributionincokingprocessincludestwoparts .OnepartisgoingintoCOGasH2 S ,CS ,COSandC2 H2 SH .TheotherpartisresidualincokeasFeS ,CaS ,S2 andsoon .Traditionally ,theremovalofsulfurofCOGisbysprayingammoniawaterintohotcoalgastoformammoniumsulfat… 相似文献
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Air oxidation of Cu-50Ni and Cu-70Ni alloys at 800℃ 总被引:3,自引:1,他引:2
1 INTRODUCTIONTheoxidationofunalloyedcopperandnickelhasalreadybeenstudiedindetail,butthereareratherfewstudiesonthehigh temperatureoxidationofbi naryCu Nialloys.Infact ,CuandNiformasubsti tutivesolidsolutionwithoutmiscibilitygap ,buttheiroxides ,CuOandCu2 Oa… 相似文献
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H.F.Yu ) P.Q.Liu ) W.H.Wang ) ) Department of Materials Science Engineering Shenyang Architectural Civil Engineering Institute Shenyang China ) Department of Airport CAAC Eastnorth Management Shenyang Chin 《金属学报(英文版)》1999,12(5):1038-1040
1.IntroductionInthescienceofcements,oneofthemostexcitingareashasbeenthatofMOC,MOChavebeenstudiedextensively〔14〕.However,thereisnopublisheddataontheuseofsilicafume.ItisknownthattheabundenceofMOCresourceinChinahasledtosomeappliedresearchstudiesonthisc… 相似文献
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Bond strength of W-Cu/CuCr integrated material 总被引:3,自引:0,他引:3
1 INTRODUCTIONW Cu/CuCrintegratedmaterialnowisusedaselectriccontactmaterialinhigh powerswitcher[1] .TraditionalprocessofbondingW CucompositeandCuCralloyiswelding .BecauseweldingdefectsoftenappearatW Cu/CuCrweldinginterface ,theinter facebondislowandunstable[2… 相似文献
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1 INTRODUCTIONOntheviewofgeometry ,weathertheshapeisperfectdependsuponchangeofcrownoccurredintherollingprocess.Ifthestretchingoftherollingstockintherollingprocessisneglected ,geometricaldepen denceofperfectshapecanbeexpressedas[1 ] :Ch =hHCH ( 1 )where Chisthe… 相似文献
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1 INTRODUCTIONCuCralloysareimportantcontactmaterialsforvacuuminterruptersandarewidelyusedforhighvoltageapplicationsbecauseoftheirconsiderablehighinterruptingabilityandhighvoltagewithstandingstress[1].Presently ,themainmethodsofpreparingCuCralloysinclude… 相似文献
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《中国有色金属学会会刊》1994,(2)
ABSTRACTSFROMTRANSNFsoc(Chineseedition)Vol.3,No.4,Oct.1993A003—CalculationforRandom-FuzzyReliabilityofRockSlopewithPossessing... 相似文献
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1 INTRODUCTIONCO2 shieldedarcweldingisoneoftheweldingtechnologieswithhigherefficiency ,lowerenergyconsumption ,lesshydrogencontentandhighanti ox idationability .Theshort circuittransferisamainforminCO2 arcweldingprocess ,butithastoomuchspattering ,andunsatisf… 相似文献
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Sm(CobklFe0.197Cu0.049Zr0.026)7.5 magnet with Hci of 2105 kA/m and β18-200℃ of - 0.17 % /℃ was made by sintering processing. The magnet has uniform celluler structure. The cell interior is a rhombohedarl 2 : 17 phase,and the boundary is a hexagonal 1 : 5 phase. The average cell size is 93 nm and the cell boundary thickness is 20 nm.The cells are enriched in Fe, and the cell boundaries are enriched in Cu. More Cu-riched 1 : 5 cell boundary phase would be helpful to obtain a higher coercivity and lower temperature coefficient. White secondary phase mainly consisting of Sm can decrease the coercivity of the magnets, but the closely paralleled grooves can increase coercivity. 相似文献
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Jianjun Tian Shengen Zhang Xuanhui Qu Farid Akhtar Siwu Tao 《Journal of Alloys and Compounds》2007,440(1-2):89-93
When sintered Sm(Co, Fe, Cu, Zr)z permanent magnets are prepared by metal injection molding, some organic binders are added in alloy powder, which leads to much residual carbon in the magnets. The residual carbon decreases magnetic properties and destroys the microstructure of the magnets. In this paper, the behavior of carbon in Sm(Co, Fe, Cu, Zr)z permanent magnets has been studied. The results indicate that Sm(Co, Fe, Cu, Zr)z magnets can keep excellent magnetic properties when the carbon content is below 0.1 wt.%: Br ≥ 10 kGs, Hcj ≥ 22 kOe, BHmax ≥ 25 MGOe. When the carbon content is above 0.1 wt.%, Br, Hcj and BHmax decrease with increasing carbon content evidently. Carbon consumes Zr content and forms ZrC, which reduces the volume fraction of the lamella and Sm(Co, Cu)5 phases. Thus, the cell size increases and the cellular microstructure deteriorates. When the carbon content reaches 0.43 wt.%, there is not enough Sm(Co, Cu)5 phase to form a uniform cellular microstructure. Br, Hcj and BHmax are approximate to zero. Since carbon has little influence on the content of Sm2(Co, Fe)17 phase, Ms can keep a high value (≥100 emu/g). ZrC has high melting point (3420 °C) and acts as dispersion particle in the magnets, which prevents the grains of SEM structure growing and reduces the liquid content of green compacts during sintering. Therefore, the density of the magnets decreases. 相似文献
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Shuo Wu Dong-Tao Zhang Ming Yue Yun-Qiao Wang Zhi-Feng Shang Dan Wu Jing-Ming Liang 《稀有金属(英文版)》2020,(3):250-255
Sm(Co,Cu,Fe,Zr)z magnets have drawn much attention for high-temperature applications due to their high Curie temperature,strong corrosion resistance and thermal stability.The effect of increasing Fe content on the distribution of elements and squareness(Sr) of demagnetization curves were investigated for two kinds of magnets with different nominal compositions of Sm(CobalFe0.15-Cu0.07Zr0.03)7.8 and Sm(CobalFe... 相似文献
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WANG Bowen YAN Rongge HAO Yanming CAO Shuying and WENG LingSchool of Electrical Engineering Hebei University of Technology Tianjin ChinaInternational Center for Materials Physics the Academy of Sciences Shenyang China 《稀有金属(英文版)》2003,22(1)
The structure, magnetization, and magnetocrystalline anisotropy were investigated using X-ray diffraction, vibrating sample magnetometer, and AC susceptibility-meter. It is found that the microstructure of (Sm0.5Nd0.5)2(Fe1-xCox)17 alloys is an (Sm,Nd)2(Fe,Co)17 phase with the rhombohedral Th2Zn17-type structure. The Curie temperature Tc increases with the Co concentration increasing, and the magnetization first increases as the Co content increases in (Sm0.5Nd0.5)2(Fe1-xCox)17 alloys and then decreases slowly. The easy magnetization direction (EMD) of (Sm0.5Nd0.5)2(Fe0.25Co0.75)17 is along the c-axis and a strong enhancement of the crystalline anisotropy energy constant K is produced by the addition of some Co atoms. The anisotropy energy constant reaches the maximum when x = 0.75 and then decreases slowly with the Co content further increasing. The (Sm0.5Nd0.5)2(Fe0.25Co0.75)17compound is an optical candidate for the new permanent magnet, which possesses a high magnetization, a high Curie temperature, 相似文献
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The oxidation behavior of Sm2(Co, Fe, Cu, Zr)17 alloy without and with a protective film of Cr2O3 or Al2O3 (in α form) was investigated in air at 600 °C. The Sm2(Co, Fe, Cu, Zr)17 alloy has two magnetic phases: Sm2Co17 and SmCo5. They are completely transformed into the Co- and Fe-based Co–Fe solid solutions in a deep subsurface zone of the alloy due to the internal oxidation of Sm. However, the zone of the magnetic phase transformation is effectively confined to a very shallow depth for the alloy with the films of Cr2O3 and, particularly, Al2O3. 相似文献
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简要介绍了新型高温永磁体Sm(Co ,Fe ,Cu ,Zr) z 的研究现状 ,总结了提高高温磁体的最高使用温度的方法 ,并对今后的研究方向作了评述。 相似文献
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The isotropic Sm2Fe17Nx magnetic powders were prepared by Hydrogenation-Disproportion-Desorption-Recombination (HDDR) process. The phase and microstructure evolutionary process of Sm-Fe alloy during the solidification, homogenization, HDDR and nitration processes were investigated by means of XRD, SEM, EDX and AFM. The results show that the homogeneous Sm2Fe17 alloy wassuccessfully obtained and the impurity phases and residual stress were well removed by heated at 1050 ℃ for 24 h. When heated at 800 ℃ for 1h in H2 of 0.1 Mpa, the alloy turns into SmHx and α-Fe with plenty of nanocrystals. After vacuumized at 800 ℃ for 2h the alloy recombines into Sm2Fe17 with a crystal grain size of about 85 nm.The lattice constant of the alloy increases and the expanding of the crystal cell reaches 6.28% after nitrified at 500 ℃ for 5 h. The magnetic property of isotropic bonded Sm2Fe17Nx magnets is Br=0.6704 T, Hcj = 1015 kA·m-1,( BH )max =73.7 kJ·m-3 with a density of 6.04 g·cm-3 . 相似文献
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Metal Science and Heat Treatment - The magnetic properties and the changes in the domain structure of alloy Sm(Co, Fe, Cu, Zr)7.5 are studied after different variants of heat treatment, i.e. (1)... 相似文献
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Nanocrystalline Nd2Fe14B/α—Fe permanent magnet 总被引:2,自引:0,他引:2
Nd8.5Fe75Co5Cu1Zr3Nb1B6.5bonded magnet was prepared by melt-spinning(vs=18m/s)and subsequent heat treatment(670℃,4min).Excellent magnetic properties of the bonded magnet were achieved:Br=0.68T,iHc=620.3kA/m,(BH)max=74kJ/m^3.The addition of Cu and Zr elements shows to be advantageous in improving an intrinsic coercivity and squareness of hysteresis loop,as well as energy product.In has a remarkable remanence enhancement and the isotropic saturation remanence ratio Mr/Ms is 0.83. 相似文献
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Xu Rengen Wang Xinhua Wu Jianmin Pan Hongge Chen Changpin Wang Qidong Dai Lichi Department of Materials Science Engineering Zhejiang University Hangzhou P. R. China Department Central Iron Steel Research Institute 《中国有色金属学会会刊》1999,9(1)
INTRODUCTIONItiswelknownthatSm2Fe17Nycompoundshavegoodintrinsicmagneticproperties[1].BecauseofthepoorstabilityofSm2Fe17Nyat... 相似文献