TY - GEN
T1 - Mechanism of reaction rate enhancement in direct production of LaNi5 by reduction-diffusion method
AU - Ohtsuka, Makoto
AU - Kim, Deog Yung
AU - Tagaki, Kimio
PY - 1993
Y1 - 1993
N2 - The previous experimental study on the reduction-diffusion (R-D) method to directly make a RmNi5 (Rm: La-base mischmetal) compound has suggested that a CaNi5 layer, which was formed between the RmNi5 compound and the unreacted Ni core, played an important role in enhancing the reaction rate to form the RmNi5 compound. To clarify the mechanism of the enhancement, the inter-diffusion coefficients in the LaNi5 compound were determined and diffusion experiments were undertaken for the Ni-La system at temperatures around 1373K using two kinds of diffusion couple, the Ni/Ni-La melt and the Ni/CaNi5/Ni-La melt. The morphology of the specimens after diffusion was also investigated. It was considered that slow lattice diffusion could be prevailing for the LaNi5 layer formed in the couple of Ni / Ni--La melt, while rapid grain boundary diffusion prevailed for the LaNi5 layer formed in the couple of Ni / CaNi5 Ni--La melt.
AB - The previous experimental study on the reduction-diffusion (R-D) method to directly make a RmNi5 (Rm: La-base mischmetal) compound has suggested that a CaNi5 layer, which was formed between the RmNi5 compound and the unreacted Ni core, played an important role in enhancing the reaction rate to form the RmNi5 compound. To clarify the mechanism of the enhancement, the inter-diffusion coefficients in the LaNi5 compound were determined and diffusion experiments were undertaken for the Ni-La system at temperatures around 1373K using two kinds of diffusion couple, the Ni/Ni-La melt and the Ni/CaNi5/Ni-La melt. The morphology of the specimens after diffusion was also investigated. It was considered that slow lattice diffusion could be prevailing for the LaNi5 layer formed in the couple of Ni / Ni--La melt, while rapid grain boundary diffusion prevailed for the LaNi5 layer formed in the couple of Ni / CaNi5 Ni--La melt.
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M3 - Conference contribution
AN - SCOPUS:0027808927
SN - 0873392566
T3 - First International Conference on Processing Materials for Properties
SP - 203
EP - 206
BT - First International Conference on Processing Materials for Properties
PB - Publ by Minerals, Metals & Materials Soc (TMS)
T2 - Proceedings of the 1st International Conference on Processing Materials for Properties
Y2 - 7 November 1993 through 10 November 1993
ER -