Electrochemical Implantation/displantation

我们成功地在一个带有气体净化设备的氩手套箱中建造了一个新的电解槽。用该装置在723-773K熔融的LiLi-KCl-Li：3N体系中进行了各种金属电极上的阳极电解，研究了氮的电化学注入。我们成功地形成了Ti-N、Fe-N、Al-N、Zr-N、Ga-N、Cr-N、Zn-N、SuS430-N、SuS304-N。结果表明，在熔体中加入LiH可以有效地加快氮化物的生成速度。该方法的一个特点是能够通过电解电位控制氮化物中的氮浓度。此外，由于氮化物的生长服从抛物线规律，因此氮化物生长的速率控制过程是氮原子在氮化物层中的扩散。我们还研究了不同稀土元素(RE=Y，La，Ce，Pr，Nd，Sin，Gd，Tb，Dy，Er和Yb)在某些过渡金属衬底上的电化学注入。结果表明，Ni_2Y、Ni_2La、Ni_2Ce、Ni_2PR、Ni_2、Ni_2Sm、Ni_2DY、Ni_2Yb、CoGd：_3、Pd_3Y、Pd_3La、Pd_3Ce和Si_2Er等合金相的形成速度较快。根据透射电子显微镜的分析，快速形成的原因是晶界附近原子的快速扩散所致。当快速形成的稀土合金在同一熔体中阳极极化时，可能只有稀土元素从电极上溶解，这被称为“电化学剥离”。对于电化学、脱附，稀土在合金中的浓度可以通过电解电位和电量来控制。

We succeeded in constructing anew electrolysis cell in an argon glove box having a gas purification equipment. By using this apparatus, we conducted anodic electrolysis at various kinds of metal electrodes in a molten LiCI-KCl-Li:3N system at 723-773 K to nvestigate the electrochemical implantation of nitrogen. We succeeded in the formations of Ti-N, Fe-N, Al-N, Zr-N, Ga-N, Cr-N, Zn-N, SUS 430-N, SUS304-N. It was found that the addition of LiH to the melt is effective to accelerate the formation rate of the nitrides. It is a characteristic of this method to be able to control the nitrogen concentration in nitrides by electrolysis potential. In addition, the rate controlling process in the nitride growth was found to be the diffusion of nitrogen atoms in the nitride layer since the growth obeyed the parabolic rate law. We also investigated the electrochemical implantation of various rare earths (RE) into some transition metal substrates, which was conducted by eathodic polarization of the transition metal electrodes in molten LiCI-KCI-RECI3 systems, where RE = Y, La, Ce, Pr, Nd, Sin, Gd, Tb, Dy, Er and Yb. We found that some selected alloy phases, i.e., Ni_2Y, Ni_2La, Ni_2Ce, Ni_2Pr, Ni_2Nd, Ni_2Sm, Ni_2Dy, Ni_2Yb, CoGd:_3, Pd_3Y, Pd_3La, Pd_3Ce and Si_2Er, are formed quite rapidly. According to the transmission electron microscopy, the cause of the rapid formation was indicated to be due to the fast diffusion of atoms near the grain boundaries. When the.rapidly formed rare earth alloys were anodically polarized in the same melt, it was possible to dissolve only the rare earth elements from the electrodes, which was termed "electrochemical displantation". For the electrochemical, displantation, rare earth concentrations in the alloys can be controlled by electrolysis potential and quantity of electricity.