Microstructure And Hydrogen Transportion Propertities Of V-Ni-Mo-Pd Alloy

Among the many high-purity hydrogen preparation methods,the metal membrane separation method is low in cost and high in purity.V alloy,Nb alloybased VB metal hydrogen separation membrane is usually used to join the alloy to other elements to form a solid solution to reduce hydrogen dissolution,thus solving the hydrogen embrittlement,improve service life.However,while reducing hydrogen dissolution,hydrogen diffusion properties tend to decrease.To solve this problem,Korean scientist Kim proposed that through the lattice matching mechanism can solve the problem of hydrogen embrittlement at the same time,the largest retained hydrogen permeation performance.In this paper,the lattice structure is controlled by adjusting the kind and content of solute elements in the alloy.Hydrogen dissolution and hydrogen permeation experiments were carried out for each lattice structure,and the effect of lattice structure on hydrogen dissolution and hydrogen permeation properties was summarized.In this paper,lattice structure was established by adding Ni,Mo and Pd alloy elements to V-based alloys.The lattice structures such as lattice matching,lattice compression and lattice serious compression were successfully constructed.The results show that the elements affect the structure of the V alloy lattice mainly through the atomic radius of the size and electronic structure in two ways.The Ni element compresses the V lattice because the atomic radius of the Ni element is less than V and its electronic structure tends to obtain electrons from V.The Mo element and the Pd element decrease the lattice in a small amount because the atomic radius of Mo and Pd is greater than V,but the outermost electron number is less than V,and the V lattice is compressed in a small amount.Hydrogen dissolution experiments of V alloys with different lattice structures show that the smaller the lattice hydrogen dissolution is,the smaller the dissolution of the alloy due to lattice compression,which is not conducive to hydrogen atoms dissolved in the V alloy lattice The The experimental results show that the lattice compression is more serious and the hydrogen permeation coefficient is smaller.This is because the hydrogen atoms in the V alloy in the V alloy needs to jump from one gap to another position of the gap,the transition process needs to cross the potential caused by lattice distortion,lattice distortion,the greater the potential barrier transition The more difficult,the smaller the hydrogen permeation coefficient.So the lattice-matched alloy has the best hydrogen permeation coefficient.The results show that the alloy with severe lattice compression has good hydrogen fixation resistance because of the small amount of hydrogen dissolved in the lattice compression.Therefore,the hydrogen embrittlement resistance better.