Electrochemical Implantation/displantation

我们成功地在带有气体净化装置的氩气手套箱中构造了一种新的电解池。利用该装置，在723 ~ 773 K的熔融LiCI-KCl-Li:3N体系中，对不同金属电极进行了阳极电解，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能有效地加快氮化物的形成速度。该方法的特点是可以通过电解电位控制氮化物中的氮浓度。此外，由于氮的生长服从抛物线速率规律，氮原子在氮层中的扩散是氮生长的速率控制过程。我们还研究了各种稀土（RE）在一些过渡金属衬底上的电化学注入，通过在熔融的LiCI-KCI-RECI3体系中过渡金属电极的阴极极化进行，其中RE = Y, La, Ce, Pr, Nd, Sin, Gd, Tb, Dy， Er和Yb。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。透射电镜分析表明，晶界附近原子的快速扩散是导致晶界快速形成的原因。当。快速形成的稀土合金在同一熔体中阳极极化，有可能只从电极上溶解稀土元素，这被称为“电化学位移”。对于电化学置换，可以通过电解电位和电量控制合金中的稀土浓度。

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.