The Microstructure And Properties Of Ni-Al Active Composite

Ni Al composite was prepared by 11 passes of accumulative roll bonding(ARB)of Ni and Al foil.The microstructure,hardness and reaction mechanism of the composite were studied.The relationship between the activity and the structure and properties of the composite was obtained by observing the experimental phenomena and analyzing the data.The main achievements are as follows:In the cumulative rolling process,the hard phase Ni in the composite will gradually suffer from necking and fracture.The thickness of the Ni layer will gradually become thinner.The relationship between the thickness of the Ni layer and the passes is summarized and the formula between the thinning rate and the passes is obtained by fitting.By testing the hardness of the composite,it is found that when the number of stacking passes is less than or equal to 3,the lamellar structure of Ni component causes the deformation of Al to be restrained by the integrity of the material,which leads to the abnormal increase of the overall hardness of the composite;when the number of stacking passes is n ≥ 4,the inlay effect of Ni particles in the Al component weakens the inhibition of the deformation of Al component,which makes the composite weaker The overall hardness of the material slows down with the increase of stacking passes.The influence of cumulative stacking passes on the Ni component,Al component and the overall hardness of the composite is: Al component > Ni component > Ni Al composite.Through the analysis of XRD and thermal analysis technology,it was found that the composite only completed the mechanical combination after the cumulative rolling,and did not form the metal compound between Ni and al.After the heat treatment,the metal compound between Ni and Al formed four kinds of metal compound between Ni and Al through the diffusion reaction.The activity of the composite increased with the increase of temperature and the refinement of Ni particles High.Figure 37;Table 4;Reference 53...