Residual Stress in Aluminum Alloy Sand Castings

Residual stress in aluminum 7% silicon, 0.5%mg alloy castings has been evaluated by X-ray diffraction. Straight bar and flanged bar castings are produced in green, sand mould, sodium silicate-co₂ mould and EPC mould, specimens are taken from different location of castings and these specimens are analyzed for residual stresses in X-ray diffractometer. Flanged bar castings have more residual stresses then straight bar castings. Most of the stresses are tensile in nature. As for the type of mould is concerned, the residual stresses are increasing in the order of green sand mould, sodium silicate-co₂, mould and EPC mould, residual stress in the flanged bar castings is not limited to the location of casting.