摘要
利用机械合金化方法制备了Mg-3Ni-2MnO2氢化物储氢材料,并对其吸放氢动力学性能进行了测试;利用Avrami指数研究了储氢材料吸放氢过程中相转变行为特征,利用形核长大理论建立其本征吸放氢动力学方程,并进行了计算。结果表明:利用机械合金化方法能够制备具有良好吸放氢动力学性能的储氢材料;200℃,2.5MPa条件下需要约65s的时间完成吸氢,吸氢量为6.23%(质量分数),300℃,0.1MPa条件下完成充分的放氢需要约550s的时间。吸氢过程Avrami指数约为0.5,其相变的主要过程为盘状氢化物沿厚度方向的生长;放氢过程中,根据Avrami指数的变化,其相转变特征为形核长大阶段、新相继续稳定长大阶段(无新的晶核形成)。动力学方程计算结果与试验曲线能较好的吻合;温度和压力对吸放氢动力学性能都有影响。
Mg-3Ni-2MnO2 hydrides are prepared by mechanical alloying under hydrogen atmosphere, and the absorption and desorption kinetics properties are measured. Intrinsic absorption and desorption equations are developed and calculated, The results show that these materials of excellent kinetics properties can be fabricated, and the absorption can be finished in 65 s at 200℃ and 2.5 MPa, and the hydrogen absorption capacity is 6.23% （mass）; the desorption can be finished in 550 s at 300℃ and 0.1 MPa. An Avrami index of about 0.5 indicates that the main process is the growth of discal hydride along the direction of thickness for absorption; the materials behave the character of nucleation and growth for desorption; the new phase growe steadily （no new crystal nucleus appears） according to the Avrami index. The calculated values agree well with the experimental values; the temperature and pressure have effects on the intrinsic kinetic properties .
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第2期226-230,共5页
Rare Metal Materials and Engineering
基金
哈尔滨工业大学(威海)校基金资助项目(IMJQ10000067
IMJQ10000045)
