Heat treatment and plastic deformation in Al3Ti particle reinforced 7050 aluminium alloy matrix composites.

7050 aluminium alloy metal matrix composites reinforced with different weight fractions of Al3Ti particles were fabricated using an in situ synthesis method and subsequent rolling, solution and aging treatment. The effects of Al3Ti particle content and particle size on the microstructures and mechanical properties of the composites were investigated by means of hardness measurements, optical microscopy and electron probe. We concluded that the grain size of the composites was smaller than that of the matrix alloy, and with an increase in the plastic deformation, the dispersion of particles was more uniform and fine. It was also found that the hardness of the composites increases with increasing weight fraction and decreasing particle size. By increasing the plastic deformation, the hardness of both the composites increased first and then decreased with the following deformation. In addition, the heat treatment contributed to the hardness. [ABSTRACT FROM AUTHOR]