Evaluation of Al-Mg2Si In-Situ Composites,Further Reinforced by TiC Particles afterSolution and Aging Heat Treatments

Al7Mg5Si (wt%)-TiC reinforced composites have been produced by flux assisted casting followed by solution and aging heat treatments. The TiC particle addition resulted in a refinement of primary Al grains and Mg2Si Chinese-script morphology, as well as reduction of the Mg2Si phase extent. Both, heat treatment and TiC addition have a positive effect on the microhardness of the Al matrix, as well as the hardness and the sliding wear resistance of Al7Mg5Si. A wear mechanism has been proposed. Electrochemical testing in 3.5% NaCl showed that the TiC reinforcement does not worsen the corrosion performance of Al7Mg5Si. Pitting is mainly associated with Mg2Si (pre-eutectic and eutectic) and eutectic Al in the Al-Si microconstituent.