摘要
利用Miedema理论和几何模型计算了二元合金系La M ,Ni M和三元合金系LaNi5-xMx(M =Co ,Mn ,Al,Cr ,Fe,Cu)的生成焓。对二元合金系 ,计算结果与已有实验结果在xM ≥ 70 % (摩尔分数 )范围符合得较好 ;三元合金系计算结果表明 ,当分别添加合金组元Mn ,Co ,Cr,Fe和Cu时 ,LaNi5-xMx 的生成焓不同程度地增大 ,其中Cr ,Fe和Mn的影响较大 ,而添加Al时生成焓明显减小。讨论了生成焓对合金高温氢化时发生歧化反应的影响 ,合金的生成焓越大 ,越有利于歧化反应。
Miedema theory and geometrical model were used to calculate the formation enthalpies of binary alloys La M, Ni M and ternary hydrogen storage alloys LaNi 5- x M x (M=Co, Mn, Cr, Fe, Cu, Al). For binary alloys system La M and Ni M(M=Co, Mn, Al, Cr, Fe, Cu, Ga), the calculated results are consistent well with the available experimental data in the range of x M≥70%. For the ternary alloys, the calculated results indicate that the substitution of elements Mn, Co, Fe, Cr and Cu for Ni can increase the formation enthapies of LaNi 5- x M x in different degree, and Cr, Fe, Mn have more significant effects, while the addition of Al remarkably lowers the enthalpies. The effect of the formation enthalpy on disproportionnation reaction of the alloys in the process of hydriding at high temperatures is discussed, and it is found that the greater the enthalpies of alloys are, the more favorable it is for the disproportionation reaction.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2000年第4期480-483,共4页
The Chinese Journal of Nonferrous Metals
基金
甘肃省自然科学基金!资助项目 (ZQ -96-0 62 )
