Experimental Investigation of Residual Stresses in Water and Air Quenched Aluminum Alloy Castings

Cast aluminum alloys are usually subject to heat treatment including quenching for improved mechanical properties. A significant amount of residual stresses can be developed in aluminum castings during heat treatment. This paper investigates experimentally residual stress differences between water quenched aluminum castings and air quenched ones. The residual stresses in aluminum castings were measured mainly using resistance strain rosettes hole-drilling method. Other measured methods such as Interferometric Strain/Slope Rosette (ISSR), X-ray diffraction method and neutron diffraction method were also applied in this investigation. In comparison with water quenching, air quenching significantly reduces the residual stresses.