(1. 桂林電子科技大學(xué) 廣西信息材料重點(diǎn)實(shí)驗(yàn)室，桂林 541004；
2. 中南大學(xué) 粉末冶金研究院，長沙 410083；
3. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 采用SEM和XRD等分析了Nb55-xVxTi25Co20氫分離合金(x=0, …, 25, %，摩爾分?jǐn)?shù))顯微結(jié)構(gòu)特征，研究其隨V含量的變化規(guī)律；利用氫滲透性能測試儀和Devanathan-Stachurski型電解池測量上述合金的氫滲透和氫擴(kuò)散性能，闡明合金成分、組織和性能參數(shù)之間的關(guān)系。結(jié)果表明：隨V含量的逐漸增加，初生Nb相體積分?jǐn)?shù)增加；相反地，兩相共晶減少，當(dāng)x＞10(摩爾分?jǐn)?shù))時(shí)，由于大量(Nb,V,Ti)2Co相和微量V3Co相的析出，合金中由兩相轉(zhuǎn)變?yōu)樗南嘟M織；伴隨上述過程，合金滲氫性能和抗氫脆性能先增加而后急劇降低，當(dāng)x=10時(shí)，Nb45V10Ti25Co20在673 K具有最大的滲氫性能，即3.76×10-8 mol/(m？s？Pa1/2)，是相同實(shí)驗(yàn)條件下Pd膜的2.4倍。另外，氫擴(kuò)散系數(shù)隨著x值的增加而增加，相反地，氫溶解度隨之降低，由此證實(shí)前者是導(dǎo)致該系列合金氫滲透性能變化的主要原因。
關(guān)鍵字: Nb55-xVxTi25Co20 氫分離合金；顯微組織；氫滲透性能
（1.Guangxi Key Laboratory of Information Laboratory, Guilin University of Electronic Technology, Guilin 541004, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:At present, group 5B metals (i.e. Nb, V and Ta) and their alloys have become one of the most promising hydrogen separation membrane materials to replace the traditional Pd membrane in the future. However, they are far from the standards proposed by the international department of energy. Hence, it is urgent to develop new hydrogen permeation membrane materials. With these considerations in mind, Nb55-xVxTi25Co20 hydrogen separation alloys (x=0, …, 25, %) were investigated systematically. Firstly, the microstructure characteristics were analyzed by SEM and XRD, and their variation rule with V content was also obtained. After that, to clarify the relationships among alloy composition, microstructure and performance parameters, the hydrogen permeability and diffusion properties of these alloys were measured by hydrogen permeability tester and Devana than-Stachurski electrolytic cell. The results show that, with the gradual increase of V content, the volume fraction of primary Nb phase increases but the two-phase eutectic decreases in these alloys. When the V content is more than 10% (mole fraction), a large amount of (Nb,V,Ti)2Co phase and a small amount of V3Co phase precipitates in the alloys. As a results, it is transformed into a four-phase structure. With these changes, the hydrogen permeability and hydrogen embrittlement resistance increases first, and then decreases sharply. When x is 10, Nb45V10Ti25Co20 alloy exhibits the highest hydrogen permeability at 673 K, i.e. 3.76×10-8 mol/(m？s？Pa1/2), which is 2.4 times than that of pure Pd. In addition, with the increase of x value (V content), the hydrogen diffusion coefficient (D) of the alloys increase whereas the hydrogen dissolution coefficient decrease (K), which demonstrates that the variation of for these membranes is due to the change in D rather than K.
Key words: Nb55-xVxTi25Co20 hydrogen separation alloy; microstructure; hydrogen permeability
