Accumulative roll bonding (ARB) of the composite coated strips to fabricate multi-component Al-based metal matrix composites

摘要

A multi-component Al-based metal matrix composite was fabricated by accumulative roll bonding (ARB) of the composite coated strips. The Ni/SiC composite layer with three different thicknesses of about 25, 50 and 150 μm was generated on the Cu substrate by electroplating. The coated strips were placed between two Al strips and processed by ARB up to eight cycles to fabricate the multi-component Al-Cu-Ni/ SiC composites. To investigate the microstructure evolution during ARB, an Al-Cu-Ni composite was produced by the same method and using the Cu strips coated with single Ni layer. After eight ARB cycles, the microstructure of Al-Cu-25Ni/SiC composite revealed a uniform distribution of the reinforcements and good bonding at the interfaces. In Contrast, the microstructure of Al-Cu-50Ni/SiC and Al-Cu-150Ni/ SiC composites was characterized by cavities and debonding at interfaces and non-uniformity of the reinforcments. The Al-Cu-25Ni/SiC composite exhibited the highest tensile strength of about 310 MPa, in comparison to the annealed Al (47 MPa). The lowest tensile strength was achieved in the Al-Cu-150Ni/ SiC composite (about 206 MPa) due to the formation of the cavities and debonding at the interfaces. Fracture surface of the composites revealed a combination of brittle and ductile fracture.