Characteristics of mechanically alloyed Cu, C and Cr mixed powders

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｉｍｐｏｒｔａｎｔｒｅａｓｏｎｔｏｈｉｎｄｅｒｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆＣｕ ｂａｓｅｄｍａｔｅｒｉａｌｓｉｓｔｈｅｉｒｉｎｆｅｒｉｏｒｍｅｃｈａｎｉｃａｌ ｐｒｏｐｅｒｔｉｅｓ.ＴｈｅｄｉｓｐｅｒｓｉｏｎｓｔｒｅｎｇｔｈｅｎｉｎｇＣｕ ｂａｓｅｄｍａｔｅｒｉａｌｓｐｒｏｄｕｃｅｄｂｙｃａｓｔｉｎｇｏｒｉｎｎｅｒ ｏｘｉｄｉｚｉｎｇｈａｖｅｎｏｗｂｅｅｎ ｐｕｔｉｎｔｏｐｒａｃｔｉｃａｌｕｓａｇｅｉｎｓｏｍｅｄｅｖｅｌｏｐｅｄｃ…     

Phase diagram of R-Fe-Co pseudoternary system with R≤33.3%(mole fraction,R=Sm0.5Dy0.5)

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｔｗｏｓｕｃｃｅｓｓｆｕｌｆａｍｉｌｉｅｓｏｆｒａｒｅ ｅａｒｔｈｃｏｂａｌｔｐｅｒｍａｎｅｎｔｍａｇｎｅｔｓｐｒｏｄｕｃｅｄｃｏｍｍｅｒｃｉａｌｌｙａｒｅＳｍＣｏ5ａｎｄＳｍ2 Ｃｏ17.ＴｈｅＳｍＣｏ5ｍａｇｎｅｔｓｈａｖｅｂ     

Removal of sulfur in coke oven gas by mixing ZnO-based additive into coal

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｕｌｆｕｒｄｉｓｔｒｉｂｕｔｉｏｎｉｎｃｏｋｉｎｇｐｒｏｃｅｓｓｉｎｃｌｕｄｅｓｔｗｏｐａｒｔｓ .ＯｎｅｐａｒｔｉｓｇｏｉｎｇｉｎｔｏＣＯＧａｓＨ2 Ｓ ,ＣＳ ,ＣＯＳａｎｄＣ2 Ｈ2 ＳＨ .ＴｈｅｏｔｈｅｒｐａｒｔｉｓｒｅｓｉｄｕａｌｉｎｃｏｋｅａｓＦｅＳ ,ＣａＳ ,Ｓ2 ａｎｄｓｏｏｎ .Ｔｒａｄｉｔｉｏｎａｌｌｙ ,ｔｈｅｒｅｍｏｖａｌｏｆｓｕｌｆｕｒｏｆＣＯＧｉｓｂｙｓｐｒａｙｉｎｇａｍｍｏｎｉａｗａｔｅｒｉｎｔｏｈｏｔｃｏａｌｇａｓｔｏｆｏｒｍａｍｍｏｎｉｕｍｓｕｌｆａｔ…     

Oxygen diffusion in c-textured epitaxial YBa_2Cu_3O_(7-δ) thin films

1　ＩＮＴＲＯＤＵＣＴＩＯＮＥｖｅｒｓｉｎｃｅｔｈｅｉｎｔｒｏｄｕｃｔｉｏｎｏｆｐｈｙｓｉｃａｌｖａｐｏｒｄｅ ｐｏｓｉｔｉｏｎｔｏｔｈｅｅｐｉｔａｘｉａｌｇｒｏｗｔｈｏｆｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓｕｐｅｒｃｏｎｄｕｃｔｉｎｇｃｕｐｒａｔｅｓ ,ｔｈｅｑｕａｌｉｔｙｏｆｔｈｅｍａｔｅｒｉａｌｈａｓｂｅｅｎ ｇｒｅａｔｌｙｉｍｐｒｏｖｅｄ[1,2 ] .Ａｔ ｐｒｅｓｅｎｔ,ｈｉｇｈｑｕａｌｉｔｙＹＢａ2 Ｃｕ3 Ｏ7-δ(ＹＢＣＯ)ｆｉｌｍｓｗｉｔｈＴＣ>90Ｋ ,ＪＣ>10 6 Ａ/ｃｍ2 ａｔ 77Ｋｃａｎｂｅｅａｓｉｌｙｐ…     

Air oxidation of Cu-50Ni and Cu-70Ni alloys at 800℃

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｏｘｉｄａｔｉｏｎｏｆｕｎａｌｌｏｙｅｄｃｏｐｐｅｒａｎｄｎｉｃｋｅｌｈａｓａｌｒｅａｄｙｂｅｅｎｓｔｕｄｉｅｄｉｎｄｅｔａｉｌ,ｂｕｔｔｈｅｒｅａｒｅｒａｔｈｅｒｆｅｗｓｔｕｄｉｅｓｏｎｔｈｅｈｉｇｈ ｔｅｍｐｅｒａｔｕｒｅｏｘｉｄａｔｉｏｎｏｆｂｉ ｎａｒｙＣｕ Ｎｉａｌｌｏｙｓ.Ｉｎｆａｃｔ ,ＣｕａｎｄＮｉｆｏｒｍａｓｕｂｓｔｉ ｔｕｔｉｖｅｓｏｌｉｄｓｏｌｕｔｉｏｎｗｉｔｈｏｕｔｍｉｓｃｉｂｉｌｉｔｙｇａｐ ,ｂｕｔｔｈｅｉｒｏｘｉｄｅｓ ,ＣｕＯａｎｄＣｕ2 Ｏａ…     

ABSTRACTS FROM TRANS NFSOC(CHINESE EDITION)VOL.3NO.4,OCT.1993

ＡＢＳＴＲＡＣＴＳＦＲＯＭＴＲＡＮＳＮＦｓｏｃ（Ｃｈｉｎｅｓｅｅｄｉｔｉｏｎ）Ｖｏｌ．３，Ｎｏ．４，Ｏｃｔ．１９９３Ａ００３—ＣａｌｃｕｌａｔｉｏｎｆｏｒＲａｎｄｏｍ－ＦｕｚｚｙＲｅｌｉａｂｉｌｉｔｙｏｆＲｏｃｋＳｌｏｐｅｗｉｔｈＰｏｓｓｅｓｓｉｎｇ...     

PROCESSING, MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Mo SILICIDES AND THEIR COMPOSITES

１　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｕｃｃｅｓｓｏｆｍａｎｙｃｕｒｒｅｎｔｏｒｐｒｏｐｏｓｅｄａｄｖａｎｃｅｄａｅｒｏｓｐａｃｅｐｒｏｇｒａｍｓｉｎＣｈｉｎａｒｅｑｕｅｓｔｓ，ｔｏａｌａｒｇｅｅｘｔｅｎｔ，ｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｎｅｗｍａｔｅｒｉａｌｓａｎｄｐｒｏｃｅｓｓｉｎｇｔｅｃｈｎｏｌｏｇｉｅｓ．Ｉｎｔｅｒｍｅｔａｌｌｉｃｓ，ｔｉｔａｎｉｕｍａｌｕｍｉｎｉｄｅｓｉｎｐａｒｔｉｃｕｌａｒ，ａｒｅｐｒｏｍｉｓｉｎｇｃａｎｄｉｄａｔｅｓｆｏｒａｐｐｌｉｃａｔｉｏｎｓｉｎｔｈｅａｄｖａ…     

Formation mechanism of laser-clad gradient thermal barrier coatings

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＺｒＯ2 ｃｅｒａｍｉｃｓｗａｓｓｅｌｅｃｔｅｄａｓｔｈｅｍａｔｅｒｉａｌｏｆｔｈｅｒｍａｌｂａｒｒｉｅｒｃｏａｔｉｎｇｓ (ＴＢＣｓ)ｆｏｒｉｔｓｈｉｇｈｍｅｌｔ ｉｎｇ ｐｏｉｎｔａｎｄｈｉｇｈｅｘｐａｎｓｉｏｎｃｏｅｆｆｉｃｉｅｎｔ[1].ＴｈｅｍｅｔｈｏｄｔｏｐｒｏｄｕｃｅＴＢＣｓｗａｓｕｓｕａｌｌｙｐｌａｓｍａｓｐｒａｙｉｎｇｔｅｃｈｎｉｑｕｅ.Ｔｈｅｐｏｒｏｓｉｔｙｉｎｔｈｅｃｏａｔｉｎｇａｎｄｔｈｅｐｏｏｒａｄｈｅｒｅｎｃｅｂｅｔｗｅｅｎｃｏａｔｉｎｇａｎｄｓ…     

THE PROPERTIES OF SILICA FUME MAGNESIUM OXYCHLORIDE CEMENT MATERIALS

１．ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｓｃｉｅｎｃｅｏｆｃｅｍｅｎｔｓ,ｏｎｅｏｆｔｈｅｍｏｓｔｅｘｃｉｔｉｎｇａｒｅａｓｈａｓｂｅｅｎｔｈａｔｏｆＭＯＣ,ＭＯＣｈａｖｅｂｅｅｎｓｔｕｄｉｅｄｅｘｔｅｎｓｉｖｅｌｙ〔１４〕．Ｈｏｗｅｖｅｒ,ｔｈｅｒｅｉｓｎｏｐｕｂｌｉｓｈｅｄｄａｔａｏｎｔｈｅｕｓｅｏｆｓｉｌｉｃａｆｕｍｅ．ＩｔｉｓｋｎｏｗｎｔｈａｔｔｈｅａｂｕｎｄｅｎｃｅｏｆＭＯＣｒｅｓｏｕｒｃｅｉｎＣｈｉｎａｈａｓｌｅｄｔｏｓｏｍｅａｐｐｌｉｅｄｒｅｓｅａｒｃｈｓｔｕｄｉｅｓｏｎｔｈｉｓｃ…     

Study on electrochemical surface modification of coal by FTIR and Raman spectra

1　ＩＮＴＲＯＤＵＣＴＩＯＮＨｉｇｈｓｕｌｆｕｒｃｏａｌｏｃｃｕｐｉｅｓａｌａｒｇｅ ｐａｒｔｏｆｔｈｅｗｈｏｌｅｄｅｐｏｓｉｔｏｆｃｏａｌｉｎｔｈｅＳｏｕｔｈ ＷｅｓｔａｎｄｔｈｅＥａｓｔｏｆＣｈｉｎａ .Ｗｉｔｈｏｕｔｗａｓｈｉｎｇａｎｄｄｅｓｕｌｆｕｒｉｚａｔｉｎｇ ,ｔｈｅｃｏｍｍｅｒｃｉａｌｃｏａｌｉｓｏｆｌｏｗｑｕａｌｉｔｙ ,ｌｏｗｃｏｍｂｕｓｔｉｏｎｅｆ ｆｉｃｉｅｎｃｙｗｉｔｈｌａｒｇｅｃｏａｌｗａｓｔｉｎｇ ,ｇａｓａｓｈ ,ＣＯ2 ａｎｄＮＯｘ .Ａｂｏｖｅａｌｌ,ｔｈｅｃｏｍｂｕｓｔｉｏｎ…     

Microstructure of Sm2Co17 magnets and its influence on coercivity

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.     

Behavior of residual carbon in Sm(Co, Fe, Cu, Zr)z permanent magnets

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, H_cj ≥ 22 kOe, BH_max ≥ 25 MGOe. When the carbon content is above 0.1 wt.%, Br, H_cj and BH_max 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, H_cj and BH_max 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.     

In-situ observation of magnetization reversal process of Sm(Co,Cu,Fe,Zr)_z magnets with different Fe contents

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(S_r) of demagnetization curves were investigated for two kinds of magnets with different nominal compositions of Sm(Co_(bal)Fe_(0.15)-Cu_(0.07)Zr_(0.03))_(7.8) and Sm(Co_(bal)Fe_(0.28)Cu_(0.07)Zr_(0.03))_(6.6) in this work.The magnetic properties of the magnets with higher Fe content fluctuate greatly after different solution treatments,indicating that they are more sensitive to the process temperature.The increase in Fe content can obviously enhance the cellular phase size.Meanwhile,inhomogeneous Cu distribution is observed in the Sm(Co_(bal)Fe_(0.28)-Cu_(0.07)Zr_(0.03))_(6.6) magnet,resulting in the different cellular structures and corresponding magnetic domain patterns in different regions in the inner grains.Furthermore,the lower Cu content regions are responsible for the wider magnetic domain,which have weaker resistance to applied magnetic field.As a result,S_r of demagnetization curve decreases with the increase in Fe content due to the inhomogeneous Cu distribution,which was confirmed by in-situ observation of electron probe micro-analyzer(EPMA) and magneto-optical Kerr optical microscope(MOKE).     

High Temperature Oxidation and Protection of a Sm2(Co,Fe,Cu,Zr)17 Alloy

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.     

Structural and magnetic properties of (Sm_0.5Nd_0.5)_2(Fe_(1-x)Co_x)_(17)compounds

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,     

新型高温稀土永磁体的研究概况

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。     

Nanocrystalline Nd2Fe14B／α—Fe permanent magnet

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.     

Magnetic Properties and Domain Structure of Alloy Sm(Co,Fe, Cu,Zr)7.5 in Different Stages of Heat Treatment

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)...     

Preparation of isotropic Sm2Fe17Nx magnetic powders and their bonded magnets

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 .     

几种常用永磁材料的磁通温度特性

对磁路设计人员来说,精确知道不同种类磁体在不同温度范围内的磁性能随温度的变化情况是非常有用的,本文对Alnico、Sm2Co17、普通Nd-Fe-B、低温度系数Nd-Fe-B四种磁体的可塑磁通在室温-120℃温度区间内的变化情况及其不同温度区间的平均温度系数进行了详细测量,得到了一些对磁路设计人员较有用的结果。