Microstructural and mechanical properties of AA 2024 alloy cast developed using a novel microwave energy-based continuous casting approach

Nowadays, utilization of microwave heating technique to process metallic materials is emerging due to its unique features, such as energy efficiency and reduced processing time due to volumetric and rapid heating evolved at molecular level. In the present study, microwave energy was exploited to fabricate AA 2024 alloy cast through continuous casting route. Results showed a marginal enhancement (0.68 ± 0.03%) in density for cast alloy. Microstructure analysis revealed the formation of heterogeneous microstructure comprising a combination of equiaxed and columnar grains. The grain size varied in the range of 85.73 ± 48.74 to 118.53 ± 44.39 μm and 93.83 ± 47.94 to 115.82 ± 51.72 μm in transverse and longitudinal cast segments, respectively, along the cast. In solidification direction, eutectic phase distribution showed a variation of 7.32 ± 0.52 to 5.54 ± 0.45% and 7.42 ± 0.48 to 5.60 ± 0.44% for transverse and longitudinal segments, respectively. XRD analyses confirmed AlCu, Al2Cu, and Al2CuMg intermetallic phases within cast alloy. Microhardness was recorded upto 124.76 ± 26.20 HV and 128.75 ± 36.02 HV in transverse and longitudinal directions, respectively. Improvements of 7.16% and 10.86% were noted in ultimate tensile strength and elongation, respectively.