Young＇s Modulus Anisotropy and Magnetomechanical Damping of [110] Oriented Tb0.3Dy0.7Fe1.95 Alloy

The △E effect and the magnetoelastic or magnetomechanical damping of vibrations in [110] oriented Tbo.aDyo.TFe1.95 alloy are experimentally studied by quasi-static stress-strain measurements under various constant magnetic fields between 0 and 3000 Oe, where stress ranges are taken from about 0 to -25, -50, -75 MPa. The linear stressstrain behaviour is obtained when the magnetic field is high enough （9000 Oe）. However, the modulus E varies with the angle θ between the compressive stress and magnetic field （9000 Oe）, which shows that the anisotropy of the modulus E is related to the magnetic domain distribution.     

X-Ray Magnetic Circular Dichroism Measurement of Fe-Co Alloy Films Prepared by Electrodeposition

The macro- and micro-magnetic properties of Fe-Co alloy films eletrodeposited on CaAs（100） are studied by synchrotron radiation x-ray magnetic circular dichroism （XMCD） in combination with the magneto-optical Kerr effect （MOKE） measurements and magnetic force microscopy （MFM）. The orbital and spin magnetic moments of each element in the Fe-Co alloy are determined by the sum rules of XMCD. Element-specific hysteresis loops （ESHL） are obtained by recording the La MCD signals as a function of applied magnetic field. MOKE results reveal that the amorphous films are magnetically isotropic in the surface plane. The MFM image shows that the dimension of the magnetic domains is about 1-2 #m, which is much larger than that of the grains, indicating that there are intergranular correlations among these grains. Both ESHL and MOKE hysteresis loops indicate the strong ferromagnetic coupling of Fe and Co in the alloy films.     

Effective Atomic Numbers for Fe-Mn Alloy Using Transmission Experiment

The effective atomic numbers （Zeff ） and effective electron density （Ne ） for Fe-Mn alloy with different Mn contents are calculated using the mass attenuation coefficients μ/p obtained via XCOM in the photon energy range of i keV-1 GeV. The results are compared with the values measured at the photon energy of 662, 1170 and 1332keV.     

Investigation on stability of directionally solidified CBr4-C2Cl6 lamellar eutectic by using multiphase field simulation

With the multiphase field method, the stability of lamellar basic state is investigated during the directional solidification of eutectic alloy CBr4-C2Cl6. A great number of lamellar patterns observed in experiments are simulated, and a stability diagram for lamellar pattern selections is presented. The simulated growth behaviours of these patterns are found to be qualitatively consistent with Karma et al＇s numerical calculations and experimental results. The formation of the primary instability is attributed to the destabilization of solute boundary layer.     

镁合金稀土阻燃机理电子理论研究

通过计算机软件建立镁合金的晶体，液态及其固/液界面模型.采用递归法计算了稀土元素在α-Mg、固/液界面、镁液态等原子环境中的环境敏感镶嵌能，定义并计算了Mg，La及Y与氧的原子亲和能.计算结果表明：La，Y在镁晶体中的环境敏感镶嵌能较高，不能稳定固溶于晶体中，因此在固体中的溶解度较小.合金凝固时稀土元素扩散到环境能较低的液体中，向液面聚集.由于稀土与氧的原子亲和能低于镁与氧的亲和能(镁、稀土与氧的亲和能分别为Mg-O：-14.9338 eV，La-O：-19.0608 eV，Y-O：-19.5050 eV     

Crystallization of the Amorphous Zr70Cu20Ni10Alloy

Crystallization Behaviour of the amorphous Zr70Cu20Ni10 alloy within the supercooled liquid region has been investigated by means of differential scanning calorimetry(DSC) and transmission electron microscopy(TEM).It is found that the relationship between the incubation time,which is necessary for the amorphous Zr70Cu20Ni10 alloy to nucleate and grow,and the annealing temperature obeys an exponential function.A similar relationship can also be observed between the peak time corresponding to the minimum of the exothermic reaction in the DSC scan and the annealing temperature,TEM observations confirm that the first exothermic peak in the DSC trace of amorphous Zr70Cu20Ni10 alloy mainly corresponds to the precipitation of the Zr2Cu phase,while the second peak mainly corresponds to the precipitation of the nanoscale Zr2Ni phase.     

国产非晶磁芯应用于感应加速组元的可行性研究

介绍了国产非晶合金应用于感应加速组元的可行性研究的初步结果.采用国产1K101型铁基非晶合金(FeSiB)带材,研制了非晶磁芯,并利用加速腔(或实验腔)对研制的非晶磁芯的磁性能、绝缘性能和稳定性等方面进行了研究.高压单脉冲实验可获得脉冲幅度为240kV、脉冲前沿为17璐(10%-90%)、脉冲平顶为72ns(±1%)的单脉冲;高压猝发三脉冲实验可获得前沿35ns、脉冲平顶60ns的三脉冲,磁芯的有效平均磁密跳变为1.41T.耐压实验研究中,得到了电压幅值为282kV的三脉冲.非晶磁芯的性能稳定,满足感应加速组元对磁芯性能的要求.     

Al-Si合金熔体的氢含量及其对铍焊接气孔的影响

铍为脆性材料，在焊接时容易使焊缝开裂。为了防止焊缝开裂，途径之一是加延展性比较好的金属或合金(如Al-Si合金或银等)作填充材料进行钎接焊。但是，铍在非真空条件下焊接，在焊缝中出现的主要缺陷是焊接气孔和缩孔。人们早已知道，纯铝在焊接或铸造时的加热过程中会吸收环境中的氢，冷却时熔体要释放氢从而形成以氢为特征的氢气孔，进而影响铝加工的质量。这表明铝及铝合金焊接形成的气孔主要是与焊接时熔体的氢含量有关。那么，在加Al-Si合金焊接铍时，产生的气孔是否也与氢含量的关系，Al-Si合金熔体随温度升高氢含量有何变化趋势，Al-Si合金中的Si对铝熔体的吸氢起何作用。