Fabrication and characterization of Al/SiCp composites by CAR process

Metal matrix composite strips are conventionally produced by strip casting technology and ingot casting followed by secondary mechanical processes. These composites usually suffer from poor distribution of the reinforcement particles, presence of porosity, and unsuitable bonding between reinforcement and matrix, which result in low mechanical properties. In order to eliminate these problems, CAR (continual annealing and roll-bonding) process was used in this study as a very effective method for manufacturing Al/SiCp composite strip. The microstructure of the fabricated composite after fifteen CAR cycles showed an excellent distribution of SiC particles in the aluminum matrix without any noticeable porosity. The results also indicated that when the number of cycles increases, the tensile strength of the produced composites improves, but their ductility and formability index decreases at first and then increases. The tensile strength and formability index of the fifteen cycle CARed composite were 1.58 and 1.23 times higher than those of the initial alloy, respectively, while the elongation value decreased slightly.

Research highlights
► Increasing the number of CAR cycles improved the uniformity of composites.
► When the number of cycles increased, first porosity increased and then decreased.
► The tensile strength of the composite increased with the number of CAR cycles.
► The elongation decreased in the first step, but increased in the second step.
► When the number of CAR cycles increased, the elastic modulus increased.