Fe替代Ni对铸态及快淬态La0.7Mg0.3Co0.45Ni2.55-xFex (x = 0-0.4)电极合金循环稳定性的影响

Influence of Substituting Ni with Fe on Cycle Stabilities of as-Cast and as-Quenched La0.7Mg0.3Co0.45Ni2.55-xFex (x = 0-0.4) Electrode Alloys

摘要:

用铸造及快淬工艺制备了La0.7Mg0.3Co0.45Ni2.55-xFex (x = 0, 0.2, 0.3, 0.4)电极合金，研究了Fe替代Ni对合金循环稳定性及微观结构的影响。结果表明，Fe替代Ni显著地改善合金的循环稳定性，且Fe替代Ni对快淬态合金的循环稳定性具有更加显著的作用。试验合金具有多相结构，包括2个主相(La,Mg)Ni3和LaNi5以及1个残余相LaNi2。Fe替代Ni促进快淬态合金形成类非晶结构，随Fe含量的增加，快淬态合金的晶粒显著细化，合金的晶格常数及晶胞体积显著增大。

Abstract:

The electrode alloys La0.7Mg0.3Co0.45Ni2.55-xFex (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by casting and rapid quenching. The influences of the substitution of Fe for Ni on their cycle stabilities as well as their structures were investigated in detail. The results indicate that the substitution of Fe for Ni significantly improves the cycle stability of the alloys, and the positive impact of such a substitution on the cycle stability of the as-quenched alloy is much larger than that of the as-cast. All of the alloys have multiphase structures composed of two major phases, (La, Mg)Ni3 and LaNi5, and a residual phase LaNi2. The substitution of Fe for Ni helps the formation of a like amorphous structure in the as-quenched alloy. With the increase of Fe content, the grains in the as-quenched alloy are significantly refined, and the lattice constants and the cell volumes of the alloys are obviously enlarged.