چكيده به لاتين
In this study, aluminum and nickel foil composites were produced using an Accumulative roll bonding (ARB) and repeated for up to five cycles, aluminum and nickel composites. In this regard, the arrangement of the foils was considered as two composites with different volume and weight percent. Composite A with a weight percentage of Al 34-Ni 66 equal to the volume percentage of Al63-Ni37 and the foils arrangement was done as one in between after surface preparation. Composite B with a weight percentage of Al 55-Ni 45 equal to the volume percentage of Al80-Ni20 and the foils arrangement was done as a nickel foil between two aluminum foils. The results of scanning electron microscopy show that with increasing stages of ARB, the nickel layers lose their attachment and diffuse into aluminum substrates. Also, increase the number of steps, the thickness distribution of the nickel layers becomes uniform. By the process of heat treatment at temperatures of 200, 250 and 300 ° C on the composites manufactured the intermetallic compound phase in the common season of nickel and aluminum layers begins to germinate and grow. Optical microscopy(OM) was used to study the microstructure. The bonding of the layers and the joint segments between them were investigated using optical microscopy and scanning electron microscopy (SEM).
To evaluate the mechanical properties, uniaxial tensile tests were performed at room temperature. The results of the tensile test show that after the preparation of the first cycle, the yield strength And the tensile strength has increased significantly compared to the original foils It is noteworthy that the tensile strength of composites A and B after the first cycle reaches 214 and 207 MPa, respectively. As the temperature rises, the yield strength and tensile strength decrease and the length of the composites increases. The trend of changes in tensile strength and increasing the length of composite samples A and B is largely similar. Annealing operations at 300. C significantly reduce the strength due to the formation of a high-hardness crisp interlayer in the Al / Ni joint.
Keywords: Accumulative roll bonding; Aluminum-Nickel composite; Microstructure; Tensile properties.
