Comparison Study of As-Cast and T6 Condition of Microstructure, Bending Strength and Double Shear Strength of A356 Alloy by Gravity, Vacuum and Squeeze Casting

The hardness, bending strength, and double shear strength of A356 aluminium alloy was studied under as cast and T6 heat treatment conditions obtained with gravity casting, vacuum casting and squeeze casting methods. The results of these three casting methods have been compared. The hardness, bending strength of A356 alloy after T6 obviously increased; the hardness value of both vacuum casting and squeeze casting has been found to be 62 HRB which is relatively high compared to gravity casting. The bending strength of gravity casting is 299 MPa (22% increase) compared to vacuum casting. However, after T6 heat treatment, the double shear strength values of all these three castings decreases.