新型氢纯化与分离膜的制备及其性能

IMR OpenIR

	新型氢纯化与分离膜的制备及其性能
	熊良银
学位类型	博士
导师	戎利建 ; 刘实
	2010
学位授予单位	中国科学院金属研究所
学位授予地点	北京
学位专业	材料加工工程
关键词	氢纯化与分离氢渗透系数复合膜
摘要	"通过向Nb中添加Fe、Ti、Ni、Zr等合金元素制备了Nb-Fe、Nb-Ti-Ni和Nb-Ti-Zr-Ni多元合金，三类合金均具有共晶组织包围先析出相(BCC-Nb)复相组织特征。合金元素对多元合金的氢渗透系数存在显著的影响，Nb-Ti-Ni合金的氢渗透系数随着Ti、Ni合金元素含量的升高而降低，其最大氢渗透系数与纯Pd相当；Nb-Ti-Zr-Ni合金的氢渗透系数随着Zr含量的升高而增加，甚至高于PdAg合金。先析出相中固溶的合金元素的类型及数量的变化，导致氢在先析出相中的溶解及扩散性能发生变化，先析出相的氢渗透系数随之改变；共晶组织化学成分及相组成的改变，也改变了共晶组织的氢渗透系数；此外，合金元素还使先析出相和共晶组织的体积份数发生了变化，并最终影响了合金的氢渗透系数。探讨了合金元素对合金抗氢脆性能影响的作用机制：合金元素的添加，一方面形成了共晶组织包围先析出相的组织结构，改变了合金的力学性能；另一方面，共晶组织的生成改变了先析出相的吸氢膨胀特性，并对Nb吸氢时的氢化物转变具有抑制作用。合金元素的添加提高了氢渗透合金的抗氢脆性能。设计并制备了具有致密金属膜-多孔支撑体复合结构的Pd/Nb40Ti30Ni30/Pd/ 多孔Ni支撑体复合膜。选择既具有较高氢渗透系数又抗氢脆性能良好的Nb40Ti30Ni30合金作为表面金属膜层，在氢纯化过程中起氢选择性渗透作用；而多孔Ni支撑体帮助表面金属膜承受渗透压力差产生的应力，使复合膜具有良好的力学性能。探讨了复合膜的制备工艺，测定了氢在复合膜中的氢渗透性能，并对氢在复合膜中的渗透行为进行了研究。Pd/Nb40Ti30Ni30/Pd/ 多孔支撑体复合膜具有氢唯一选择性渗透特征，且其氢渗透通量高于相同条件下纯Pd的性能。Pd/Nb40Ti30Ni30/Pd/ 多孔支撑体复合膜具有替代Pd及PdAg合金而用作新型氢纯化与分离膜的应用潜力。"
其他摘要	"The thesis is focusing on the development of new hydrogen permeation membranes for the separation and purification of hydrogen gas. Nb-Fe, Nb-Ti-Ni and Nb-Ti-Zr-Ni alloys were fabricated by adding Fe, Ti, Ni and Zr in Nb. Microstructure of the three alloys were characterized by eutectic phase (BCC-Nb) surrounded by primary BCC-Nb solid solution. It was evident that the hydrogen permeability of the Nb-Ti-Ni alloys decreased with increasing contents of Ni and Ti, the maximum hydrogen permeability equaled to pure Pd. It was also proved that the hydrogen permeability of the Nb-Ti-Zr-Ni alloys increased with Zr addition. The maximum hydrogen permeability is even a little higher than that of the PdAg alloy. As to the change of the Ti, Ni and Zr addition, the hydrogen permeability of the primary BCC-Nb phase alternated because of the variation content of the Ti, Ni and Zr elements solute in BCC-Nb phase. Due to the alternation of the chemical composition and phase structure for the eutectic phase, hydrogen permeability of the eutectic phase changed as well. Furthermore, the Ti, Ni and Zr addition also influence the volume fraction of the primary phase and the eutectic phase. Conclusively, the hydrogen permeability of the Nb-Ti-Ni and Nb-Ti-Zr-Ni alloys changes with Ti, Ni and Zr addition. Results about effect of alloy additions on the hydrogen permeability of the above three alloys showed that the alloy additions promoted the formation of microstructure characterized by eutectic phase (BCC-Nb) surrounded by pro-eutectoid phase surrounded by eutectic structure, which lead to the change of mechanical properties. On the other hand, the expansion of the pre-eutectoid phase was change for the formation of eutectic structure, finally suppressed the formation of hydride during the process of hydrogen absorption. The addition of alloy elements increased the hydrogen embrittlement resistance of the alloys. The Pd/Nb40Ti30Ni30/Pd/ porous nickel support composite membrane for hydrogen separation and purification was designed and successfully fabricated by using multilayered magnetron sputtering method. The Nb40Ti30Ni30 alloy, which has the proven advantages of both high hydrogen permeability and satisfied resistance to hydrogen embrittlement, was used as the surface layer for selectively permeation of hydrogen gas. The porous Ni support, which was fabricated by uniaxially compressing nickel powder and sintering treatment under hydrogen circumstance, mainly sustains the stress induced by hydrogen pressure difference. Preparation technique of the Nb40Ti30Ni30 membranewas investigated for optimizing the composite membrane. Gas permeation properties of the composite membranes were studied and the hydrogen permeation mechanism was fully discussed. The membrane possesses high permeation efficiency and good mechanical property. It can be applied ass new permeation membrane in place of the Pd and PdAg alloys for hydrogen separation and purification."
文献类型	学位论文
条目标识符	http://ir.imr.ac.cn/handle/321006/64152
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	熊良银. 新型氢纯化与分离膜的制备及其性能[D]. 北京. 中国科学院金属研究所,2010.