Effect Of Rolling And Heat Treatment On Microstructure And Hydrogen Transport Properties Of Nb(W,Mo)-TiNi Hydrogen Permeable Alloys

Metal film is widely used in the field of hydrogen purification because of its goodselection permeability for hydrogen,high purity of pure hydrogen and good stability and suitable for various external environment.In the process of hydrogen separation,the hydrogen permeation flux of metal film is inversely proportional to the thickness of the membrane,and the alloy film thickness is reduced by mechanical process.It can enhance hydrogen permeation flux and increase the efficiency of hydrogen purification.The combination of rolling and heat treatment is the main processing method for mass production of hydrogen separation alloy membrane.In this paper,a combination of cold rolling and annealing is used to process the alloy films of Nb45Ti27.5Ni27.5 and Nb56Ti23Ni21 alloys based on "multiphase composition and function sharing",and to explore the microstructure and hydrogen transport properties of hydrogen separated alloys by rolling and heat treatment.Influence。The XRD and SEM results of four composition alloys after cold rolling show that the main phase of the alloy is still composed of Bcc-Nb phase and B2-Ti Ni phase,and the structure basically maintains the structure of primary Bcc-Nb phase plus eutectic [Bcc Nb+B2-Ti Ni],but the cold rolling process will change the original microstructure,that is,the cold rolling direction becomes mixed with dislocation and micro crack.A flattened tissue.The microstructure of cold rolled alloy is flat after annealing,but the dislocation microstructure and micro crack inside the cold rolled alloy have been eliminated.The hydrogen absorption test of four alloys of cold rolled state before and after annealing was carried out.The hydrogen solubility of hydrogen separated alloys with cold rolling of 50% was increased,but the increase of hydrogen solubility in the alloy adding elements W and Mo was less.The hydrogen permeation performance of the alloy shows a significant decrease in the hydrogen permeation performance of the alloy with the shape variable of 50%.When the hydrogen permeation flux reaches the highest,the hydrogen permeation performance of the cold rolled alloy can only reach 1/3 of the cast alloying alloy under the same experimental condition,and the hydrogen diffusion coefficient also decreases obviously.The correlation properties of the cold rolled alloy will change after annealing,which is manifested by the decrease of hydrogen solubility and the increase of hydrogen permeation and diffusion properties under the same experimental conditions.The cold rolled Nb46W5Mo5Ti23Ni21 alloy is used as an example to compare the experimental data before and after annealing,and after annealing at 1100 centigrade 24 h The maximum value of hydrogen permeation coefficient after treatment is 3.39×10-8mol H2m-1s-1Pa-0.5,which has basically been restored to the level of as cast alloy.