在四氢呋喃中球磨改性处理的LaMg_(11)Ni合金吸放氢特性研究

Hydriding/Dehydriding Behaviour of LaMg_(11)Ni Alloy Modified by Mechanical Grinding in Tetrahydrofuran

在四氢呋喃(THF)中对LaMg11Ni合金进行球磨改性处理.研究了改性处理对合金储氢性能的影响,并研究了THF球磨对LaMg11Ni改性的机理.观察到在较温和的温度(室温~448 K)下合金具有较高的储氢量和良好的吸氢动力学性能.在THF中球磨20 h的合金试样在448 K和3.2 MPa氢压下,初次的吸氢量达到3.4%(质量分数).放氢性能也得到了改善.XRD分析表明,在THF中球磨改性后的合金有一定程度的非晶化.

The structural and hydriding behaviours of the alloy LaMg11Ni after modification by mechanical grinding in tetrahydrofuran (THF) were investigated. The influence of mechanical grinding in THF on surface activation was evaluated by studying the hydrogen absorption/desorption kinetics. The alloy possesses high hydrogen storage and excellent kinetic behaviour, even at moderate temperatures. For the LaMg11Ni alloy milled in THF for 20 h, the hydrogen content of 3.4wt.% was obtained at 448 K and 3.2 MPa H-2 after the initial exposure to hydrogen. An even higher hydrogen content of 3.65wt.% was obtained under the same conditions after several hydriding/dehydriding cycles. Auger electron spectroscopy (AES) was used to determine the surface characteristics of the modified alloy. The modified alloy exhibits a rather high surface activity which improves with increase of milling time. According to XRD analysis the alloy modified by milling THF, show some degree of amorphousness.