由FeV80合金制备的V28Ti32Cr28Mn6Fe6合金的组织结构及吸放氢特性

Microstructure and Absorption/Desorption Properties of V28Ti32Cr28Mn6Fe6 Alloy Prepared from FeV80 Alloy

摘要:

通过XRD、SEM/EDS及PCT测试研究了由FeV80合金制备的V28Ti32Cr28Mn6Fe6合金的组织结构及吸放氢特性。该合金由bcc相和C14 Laves第二相构成。由于合金中氧含量 (0.83%, 质量分数)较高，因而吸放氢容量较低，动力学性能较差。通过添加一定量的稀土元素La (1%~10%, 质量分数)，可显著降低合金中的氧含量，从而提高其动力学性能和吸放氢容量。当La的添加量达到4.0%时，合金具有最佳的吸放氢性能，吸氢量达到3.62%，放氢量达到2.13%；合金氢化物的生成焓为(–40.0±1) kJ/mol·H2

关键词:贮氢材料;钒基贮氢合金;FeV80合金;吸放氢特性

Abstract:

The phase, microstructure and absorption/desorption properties of V28Ti32Cr28Mn6Fe6 alloy prepared from FeV80 alloy were researched by XRD, SEM/EDS and PCT measurement. The prepared alloy consists of two phases, bcc main phase and C14 Laves minor phase. This alloy shows low absorption/desorption capacities and poor absorption kinetics due to the high oxygen content of 0.83wt% originated from the FeV80 source. After addition of rare-earth metal of La, the oxygen content is obviously decreased, and the mechanical properties and absorption/desorption capacities are markedly increased. The addition of 4.0wt% La brings about the optimal hydrogen absorption and desorption properties, i.e. an absorption capacity of 3.62wt% H and desorption capacity of 2.13wt% H at 293 K. The formation enthalpy of the hydride of the 4.0wt% La containing alloy is –40.0±1 kJ/mol·H2.

Key words:hydrogen storage materials; V-based hydrogen storage alloy; FeV80 alloy; absorption/desorption properties