Electrochemical Implantation/displantation

我们成功地在具有气体净化设备的氩气手套箱中构建了新的电解槽。利用该装置，在723-773 K温度范围内，在熔融LiCl-KCl-Li：3 N体系中，对不同金属电极进行阳极电解，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、SUS 430-N、SUS 304-N。结果发现，添加LiH的熔体是有效的，以加快氮化物的形成速率。该方法的特征在于能够通过电解电位控制氮化物中的氮浓度。此外，由于氮化物生长遵循抛物线速率定律，发现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。我们还研究了在熔融LiCl-KCl-RECI_3体系中，通过过渡金属电极的阳极极化，将不同稀土（RE）离子注入到一些过渡金属基体中，其中RE = Y，La，Ce，Pr，Nd，Sin，Gd，Tb，Dy，Er和Yb。我们发现，一些选定的合金相，即，Ni_2Y、Ni_2La、Ni_2Ce、Ni_2Pr、Ni_2Nd、Ni_2Sm、Ni_2Dy、Ni_2Yb、CoGd：_3、Pd_3Y、Pd_3La、Pd_3Ce和Si_2Er等的生成速度较快。透射电子显微镜分析表明，这种快速形成的原因是由于晶界附近原子的快速扩散。当快速形成的稀土合金在同一熔体中阳极极化时，有可能只溶解电极上的稀土元素，这被称为“电化学溶解”。在电化学方面，稀土的含量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.