V40-Fe8-Ti-Cr(Ti/Cr=0.95~1.20)合金的结构与吸放氢特性

The Structures and Hydrogen Absorption-Desorption Properties of V40-Fe8-Ti-Cr(Ti/Cr=0.95~1.20) Alloys

摘要:

研究了V40-Fe8-Ti-Cr(Ti/Cr=0.95~1.20) 四元合金的结构及吸放氢性能。结果表明：不同Ti/Cr比的合金均为bcc单相结构，随着Ti/Cr比的降低，合金的晶格常数降低，平台压升高，吸氢量降低，放氢量先增加后降低；当Ti/Cr为1时，得到合金V40Ti26Cr26Fe8在298 K下具有最大的放氢量2.4%(质量分数)，平台压为0.24 MPa。通过计算得到V40Ti26Cr26Fe8的焓变ΔH和熵变ΔS分别为–39.6 kJ·mol-1H和–140.3 J·mol-1·K-1，在4

Abstract:

The structures and hydrogen absorption-desorption properties of V40-Fe8-Ti-Cr(Ti/Cr=0.95~1.20) alloys were investigated. All the studied alloys are single-phase with bcc structure. With the decrease of Ti/Cr ratio, the lattice parameters decrease, plateau pressures increase, and hydrogen absorption capacities increase first, then decrease. The V40Ti26Cr26Fe8 alloy with a Ti/Cr ratio of 1.00 has the maximum hydrogen desorption capacity of 2.4% mass fraction with a plateau pressure of 0.24 MPa at 298 K. ΔH and ΔS of the V40Ti26Cr26Fe8 alloy are –39.6 kJ·mol-1H and –140.3 J·mol-1·K-1, respectively, and its plateau pressure at 423 K is calculated to be 27.5 MPa