چكيده به لاتين
In this study, accumulative roll bonding (ARB) process was used, up to five cycles for manufacturing multilayer AA1050/AA7075 composites with the initial thickness of 500 microns. composite. In this process, the stacking of the foils was such that AA1050 alloy was taken as the matrix of the composite. The microstructure of the composites that were produced were studied by optical microscopy (OM), scanning electron microscopy (SEM) to define the connection bond and grains condition. Also, mechanical properties of the composites were assessed by uniaxial tensile test and Vickers microhardness measurement. Microscopic analysis results showed that with increasing the ARB cycle, the AA1050 and AA7075 foils did not lose their continuity that is a proper feature of the process. This characteristic was observed down to very small thickness of the layers, i.e. 10 microns. AA7075 alloy played the role of reinforcement in the composite. As the ARB cycle increased, the distribution of different layers of AA7075 and AA1050 was more uniformed. The microscopic examination indicated the presence of very small intermetallic phases in the ARB structures. These intermetallic phases were uniformly distributed up to high cycles of the ARB process. Tensile testing results showed that the yield strength was 279 MPa, tensile strength was 301 MPa, which was substantially increased compared with the initial AA1050 matrix. Though the elongation (11.9%) still remained in the AA7075 foil range. With increasing the ARB cycles, strengths were mildly increased and at the same time the ductility of the composites were increased which was indicated of the proper application of the process to produce these composites. The optimum condition of strength and ductility was obtained in five cycles of the ARB process. In this condition, the yield strength of 303 MPa, tensile strength of 330 MPa and ductility of 18.4% were obtained which is quite appropriate for industrial application.
