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1.
压缩应力下(Tb,Dy)Fe2磁致伸缩的研究   总被引:5,自引:0,他引:5  
赵玉刚  李碚 《功能材料》1994,25(4):359-361
本文利用自制的磁致伸缩测量仪和“jump”效应测量仪研究了在一定压强了多晶(Tb、Dy)Fe2棒的磁致伸缩,发现加压时,在一定工艺条件下制作的(Tb、Dy)Fe2棒会有磁致伸缩的变化。卸载后经过热处理,磁致伸缩值在不加压时也会维持一个高值。  相似文献   

2.
蒋成保  宫志凯 《功能材料》1997,28(6):570-572
研究了经超高温梯度向凝固制备的Tb0.3Dy0.7(Fe,M)1.95合金样品中存在的晶体缺陷的类型,分析其对该材料磁致伸缩性能的影响,探讨如何调整工艺来消除晶体缺陷,提高材料的磁致伸缩性能。  相似文献   

3.
稀土超磁致伸缩材料微位移机构综合实验研究   总被引:4,自引:0,他引:4       下载免费PDF全文
研究了稀土超磁致伸缩材料(Tb0.27Dy0.73)Fel.9(商品名为Terfenol-D)微型移机构的设计方法,建立了基于Terfenol-D棒的高速强力微位移机构的动态响应科技司模型,对该模型进行了计算机仿真,并与实验结果进行了比较、分析,给出了该机构的力特性、热特性,这些对基于Terfenol-D的产品真有重要的参考价值。  相似文献   

4.
用超声脉冲回波重迭法测量了超磁致伸缩材料Tb_(0.27)Dy_(0.73)Fe_(2-x)系列样品在不同磁场下的超声波速度,给出了该系列样品的弹性常数随磁场的变化情况,并对实验结果作了初步的解释和探讨。  相似文献   

5.
本文研究了轻稀土负磁致伸缩SmFe_x(1.40<x<1.94),Sm_xDy_(1-x)Fe_y(0.84<x<0.92.1.80<y<1.90),Sm_(0.90)Dy_(0.10)(Fe_(0.95)Al_(0.05))_(1.80)晶体的制备、热处理及磁学性能,发现SmFe_x合金的λ-x曲线存在两个峰值,峰值的x点随热处理发生的变化有一定的规律性,还比较了热处理前后,Sm-Fe、Sm-Dy-Fe和Sm-Dy-Fe-Al的相组成对性能的影响。热处理用于改善磁致伸缩性能,并且制得了高磁致伸缩性能的SmFe_2和(Sm,Dy)Fe_2合金。  相似文献   

6.
新型真空定向凝固装置的研制   总被引:3,自引:0,他引:3  
采用双区加热技术,成功地研制了一台新型真空定向凝固装置,其主要性能指标为:温度梯度DL=250℃/cm,最高温度1700℃抽拉速度R=0.1 ̄60mm/min,炉内真空度为0.1pa(热态),定向材料最大尺寸为φ40×350mm,可满足研制稀土超磁致伸缩Tb-Dy-Fe合金的要求。  相似文献   

7.
TbDyFe合金的组织和磁致伸缩性能   总被引:6,自引:0,他引:6  
定向凝固TbDyFe合金具有(112)择优取向,热处理能明显地改变显微镜组织和磁致伸缩性能,在1100℃真空处理2h后,磁致伸缩性能最好,空冷和炉冷对磁致伸缩性能影响不大,富稀土相的球化和晶粒吞并长大,减小了磁化过程中90°磁畴转动的阻力,是高温处理提高磁致伸缩性能的根本原因。  相似文献   

8.
本文研究外加磁场情况下,Sm0.88Dy0.12Fe2合金的微观结构,确定了低磁场下,该合金中(Sm,Dy)Fe2相由立方晶转变为正方晶系,原子发生了位移,初步分析了微观晶格畸变与宏观磁致伸缩应变的关系。  相似文献   

9.
超负磁致伸缩晶体Sm—Fe,Sm—Dy—Fe和Sm—Dy—Fe—Al的研究   总被引:1,自引:0,他引:1  
本文研究了轻稀土负磁致伸缩SmFex(1.40≤x≤1.94),SmxDy1-xFey(0.84≤x≤0.92,1.80≤y≤1.90),Sm0.90Dy0.10(Fe0.95Al0.05)1.80晶体的制备,热处理及磁学性能,发现SmFex合金的λ-x曲线存在两个峰值,峰值的x点热处理发生的变化有一定的规律性,还比较了热处理前后,Sm-Fe、Sm-Dy-Fe和Sm-Dy-Fe-Al的相组成对性能  相似文献   

10.
赵玉刚  平爵云 《功能材料》1997,28(5):474-476
利用浮区法和布里奇曼法制备Tb0.3Dy0.7Fe1.95的Terfenol-D,通过磁致伸缩系测定,发现利用浮区法制备的样品在一定的压应力下有“跳跃效 ”,利用布里奇曼法制备的样品具有较大的压力效应但没有出现“跳跃效应”。  相似文献   

11.
Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩   总被引:1,自引:1,他引:0  
采用Czochralski方法生长了Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x(1.85≤x≤1.95)取向合金。所有合金主相为立方Laves相结构,择优取向不完整择优取向的方向与X的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。  相似文献   

12.
针对两种新型稀土型储氢合金La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2的储氢特性进行研究分析。实验表明,相同温度下,La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的PCT曲线基本重合,且都具有优良的吸氢动力学性能;相比之下,后者的滞后系数要小于前者,吸氢量较大,吸氢速率也较快,故其储氢性能较优。300次吸放氢循环实验结果表明,La0.5Y0.5Ni4.8Al0.2合金的吸氢动力学性能虽然略有下降,但抗粉化性能较好。  相似文献   

13.
The thermal stability of amorphous ternary hydrides Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45) and their corre-sponding amorphous binary alloys Mg_(50)Ni_(50) and Mg_(30)Ni_(70) were studied with X-ray diffraction(XRD) and differential scanning calorimetry(DSC). Samples of the amorphous alloys were preparedby mechanical alloying and the amorphous hydrides were obtained by charging the alloys with gas-eous hydrogen at 3.0 MPa and 423 K. It was found that the amorphous hydrides released most oftheir hydrogen before the crystallization of the essentially hydrogen depleted amorphous alloy. Thecrystallization temperature of amorphous Mg_(50)Ni_(50)H_(54) elevated and that of amorphousMg_(30)Ni_(70)H_(45) did not change in relation to the original binary amorphous alloy. This is very excep-tional for amorphous hydrides. The reason for the effects of hydrogen absorption/desorption on thecrystallization of amorphous alloys was discussed.  相似文献   

14.
The surfaces of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were modified by oxygen and nitrogen plasma treatments. The physical and chemical surface characteristics were evaluated by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatments caused an increase in both contact angle and roughening, altered the surface morphology, inserted polar groups, and, consequently, enhanced the hydrophilicity for both PLLA and PHBV polymers.  相似文献   

15.
Experimental studies and analysis of acousto-optic diffraction in alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are given. Ultrasonic wave velocity, elastic compliance and stiffness coefficients, and piezo-optic and photoelastic coefficients of alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are determined. The acousto-optic figure of merit has been estimated for different possible geometries of acousto-optic interaction. It is shown that the acousto-optic figures of merit for alpha-BaB(2)O(4) crystals reach the value M(2)=(270 +/- 70) x 10(-15) s(3)/kg for the case of interaction with the slowest ultrasonic wave. The directions of propagation and polarization of those acoustic waves are obtained on the basis of construction of acoustic slowness surfaces. The acousto-optic diffraction is experimentally studied for alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals.  相似文献   

16.
Novel hybrid polymers with thiophenylanilino and furanylanilino backbones and substituted phenyl side groups are reported. The new monomers bis-(4-heterocyclic-2-yl-phenyl)-aryl-amine (heterocyclic = thiophen with aryl = 4-benzoyl (2a), 4-nitro-phenyl (2b) and furan with aryl = 4-benzoyl-phenyl (3a), 4-nitro-phenyl (3b)) were prepared by monosubstituting triphenylamine under electrophilic aromatic conditions affording 4-nitrotriphenylamine and 4-benzoyltriphenylamine. Di(bromination) of the latter compounds followed by Stille cross-coupling reactions with 2-tributylstannylthiophene or 2-tributylstannylfuran produces the new monomers 2a–b and 3a–b in high yield. The monomers are electrochemically polymerized at relatively low potentials (<0.8 V versus Ag+/AgCl) in acetonitrile electrolytes resulting in electroactive films. All the new polymers can be repeatedly oxidized and reduced with little loss of electrochemical activity. Vibrational spectroscopy reveals that the monomer units are connected predominately via coupling of the thiophenyl or furanyl rings yielding the novel polymers. Single-crystal molecular structure determinations of 4-nitrotriphenylamine and monomer 3b indicate the importance of the electron-withdrawing groups on the pendent phenyl groups in determining the extent of delocalization of the extended multi-ring systems. Molecular orbital calculations suggest that the HOMO of 2b is delocalized about both anilino and thiophenyl portions of the molecule. Electronic supplementary material  Supplementary material is available for this article at and is accessible for authorized users.  相似文献   

17.
Tao X  Wang X  Li X 《Nano letters》2007,7(10):3172-3176
Two kinds of aluminum borate nanowires, Al(4)B(2)O(9) and Al(18)B(4)O(33), were successfully synthesized by a one-step combustion method through control of the Al:B atomic ratio and synthesis temperature. Both nanowires are single crystalline but have distinguishing growth habits. Nanoindentation tests were performed directly on individual nanowires to reveal their mechanical properties. A 70% reduction in elastic modulus was found in Al(18)B(4)O(33) nanowires compared with their bulk counterpart. Al(18)B(4)O(33) nanowires exhibited higher hardness and elastic modulus than Al(4)B(2)O(9) nanowires.  相似文献   

18.
The work functions before and aftercrystallization of two glassy alloys,Pd_(83.5)Si_(16.5) andCu_(70)Ti_(30) have been measured by means of the con-tact potential difference method in the secondaryelectron field at room temperature under 10~(-5) Pavacuum.The results show that the work functionsof both glassy alloys are higher than those of thecorresponding crystalline alloys.  相似文献   

19.
20.
The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.  相似文献   

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