Executive Summary : | Technologists are working on developing high-strength aluminium alloys for automotive and aerospace applications to reduce CO2 emissions and improve fuel efficiency. Traditional methods of developing aluminium 7xxx alloy contain hard phases, inhomogeneous structures, and casting defects like porosity and shrinkage cracks. To achieve the full potential of this alloy, extensive work is being done to change the morphology of primary dendrite structure (DS) to an equiaxed spherical structure with minimal casting defects at a reasonable processing cost. Semi-solid metal processing (SSMP) is an advanced technique that can be divided into thixocasting or thixoforming and rheocasting. SSMP faces difficulties with liquid fractions exceeding 50%. Strain-induced melt activation (SIMA) is an alternative method that uses a conventionally cast starting material to deform it into an equiaxed spherical grain. The deformation during cold/warm working accumulates the structure's strain energy, which acts as a catalyst for recovery and recrystallization kinetics during heat treatment. The effect of the strain-induced melt activation process on the microstructure and mechanical properties of Al 7xxx alloy will be studied. The alloy will be prepared from the melting and casting route and further processed through the SIMA process to obtain a homogeneous structure with spherical primary grain and minimum casting defects. The amount of deformation, mushy zone heat treatment temperature, and holding temperature will be optimized experimentally and numerically. |