贮氢合金V_3TiNi_(0.56)Al_x耐碱液腐蚀性能研究

Study on the Corrosion Resistance of V_3TiNi_(0.56)Al_x Hydrogen Storage Alloys in Alkaline Solution

钒基固溶体贮氢合金V3TiNi0.56由于其可逆吸放氢量大,作为镍氢电池负极材料有很大的应用前景。但合金的耐碱液腐蚀性能差,导致合金循环寿命短达不到应用要求。主要研究了合金元素Al对钒基固溶体贮氢合金耐碱液腐蚀的影响。测试V3TiNi0.56Alx合金电极的腐蚀电位、均匀腐蚀全浸试验过程中的质量损失率和组织变化,发现:V3TiNi0.56Alx合金中Al含量增加,腐蚀电位正移,腐蚀质量损失率减小,晶界的网状结构消失速度变慢,耐碱液腐蚀性能提高。

V3TiNi0.56,one of choosed V-based solide solution hydrogen storage alloys, has been considered as promising candidates for negatie electrode materials of Ni-MH battery because of their higher reversible hydrogen storage capatites. But Va V3TiNi0.56 alloy with poor cyclic durability in alkaline solution is not for the practical use, because the corrosion resistance in alkaline solution of V3TiNi0.56 alloy is weak. In the paper, elemental Al is added to improve the corrosion resistance in alkaline solution of V3TiNi0.56 alloy. Corrosion potential, mass loss rate and structure transformation in fully-flooded uniform corrosion of V3TiNi0.56Alx alloys are tested. The results show that the increase of Al content in the alloys can shuffle corrosion potential, reduce mass loss rate in alkaline solution, impede extinction of network structure for grain boundary, and improve the corrosion resistance in alkaline solution. Key words