Effects of copper addition on the in-situ synthesis of SiC particles in Al–Si–C–Cu system

Abstract

In this research work, SiC particles have been successfully in-situ synthesized in Al–Si–Cu matrix alloy utilizing a novel liquid–solid reaction method. The effect of copper addition on the synthesis of SiC in Al–Si–C–Cu system was investigated. The composites mainly contain spherical SiC particles and θ-Al2Cu eutectic phases, which are embedded in the α-Al matrix. Results indicated that the temperature for forming in-situ SiC particles significantly reduced from 750°C to 700°C with the copper addition. The size of in-situ synthesized SiC particles can be as low as 0.2μm. Further study found that the addition of 10wt.% copper into Al–Si–C alloy causes its solidus temperature to decrease by about 65°C. Additionally, the Rockwell hardness value of SiCp/Al–18Si–5Cu composites has an average of 92, which is 50% higher than that of the sample without copper addition.