氢化燃烧法合成La1.5Ni0.5Mg17的工艺优化

采用正交实验设计方法安排实验，运用L9(3^4)优化氢化燃烧法合成La1.5Ni0.5Mg17的工艺，考察了施压制饼时间、合成保温时间、合成起始氢气压力、保温温度4个因素对储氢材料的储放氢容量和速率的影响，通过直观分析和方差分析得出优化的工艺为：保温温度903K，制饼施压时间40min，合成起始氢气压力为1MPa，合成保温时间1800min。此条件下合成储氢材料La1.5M0.5Mg17在573K的储放氢容量分别为：5．40和5．15％H(质量分数)；储放氢速率分别为：0．734和0.681％H／min。用XRD分析了材料吸氢和脱氢后的物相结构发现：用Ni适量取代La2Mg17中的La没有导致结构变化，存在的LaNi5，LaH3和La改善了材料的吸放氢速率。

Optimization of Technics for La1.5Ni0.5Mg17 by Hydriding Combustion Synthesis

The experiment was designed by orthogonal test and the technics for La_(1.5)Ni_(0.5)Mg_(17) by hydriding combustion synthesis was optimized according to L_9(3~4). The influence on hydrogen storage capacity and hydriding dehydriding rate of material was investigated and optimum hydrogen storage alloy was obtained by the technics at 903 K for 1800 min, the compressive pressure for the compact is 1 MPa for 40 min. The maximum hydrogen absorption/desorption capacities of La_(1.5)Ni_(0.5)Mg_(17) are 5.40 and 5.15 mass% H, its hydriding/dehydriding rates are 0.734 and 0.681 mass% H/min, respectively. The XRD results explain that it is no change in structure of La_2Mg_(17) after substituted with Ni for La and catalytic effect of LaNi_5, LaH_3 and La are beneficial to the improvement on kinetics property of La_(1.5)Ni_(0.5)Mg_(17) alloy.