Abstract
Squeeze casting has emerged as an attractive alternative for the casting of aluminum alloys to boost the mechanical and microstructural attributes. However, the alloys practiced in structural applications where ductility is considered a key characteristic, additional heat treatment processes are opted after casting. Considering the industrial applications of Al7050, the current study focused on manufacturing defect-free casting for structural applications. For this purpose, three key process variables including squeeze pressure (SP), melt temperature (MT) and die temperature (DT) have been preferred to improve the percentage elongation, ultimate tensile strength and hardness with minimal casting defects. Annealing treatment is preferred to further advance the ductile behavior of the squeeze-casted Al7050 alloy. Among different process variables, SP has a significant contribution in raising the mechanical properties followed by MT and DT. Taguchi-based Grey relational analysis (GRA) has been used to attain the optimal level of input parameters (SP = 135 MPa, MT, 740 degrees C and DT = 240 degrees C) for the superior microstructural and mechanical attributes simultaneously. Microstructural investigations revealed that application of high SP and DT with reasonable MT significantly improved the grain structure and minimized the typical casting defects including micro-voids, porosity and shrinkage cavities. Annealing treatment has been observed productive for improving ductility and reducing the casting defects specifically micro-porosity.