Evaluation of the Effect of Holding Temperature and Time of SIMA Process on the Microstructure and Mechanical Properties of Aluminum Alloy 2024

This study aims to investigate the effect of holding temperature and time of semi-solid SIMA process on the microstructure and mechanical properties of aluminum alloy 2024 and to compare it with T6 heat treatment. The results of scanning electron microscopy, EDX analysis and metallographic techniques showed that an increase in holding temperature and holding time would first lead to an increase in sphericity and then a decrease is observed. This process led to an increased formation of continuous eutectic microconstituent in the grain boundaries and also more cavities. The optimum cases represented an increase of 116% in elongation and 44% in toughness, and a decrease of 3.7% in strength and 5.5% in hardness in comparison with T6 heat treated sample. The results indicated the positive effects of SIMA process on the mechanical properties.