Surface stresses induced by grit blasting

Summary Stress measurements using the blind hole drilling technique with electrical resistance strain gauges have been made on surfaces of an aluminium alloy which have been subjected to a variety of grit blasting treatments. Relationships between the induced stress and depth were determined for each treatment. It is shown that the magnitude and the depth of the induced compressive stress are particularly sensitive to variations in grit size and, to a much lesser extent, to changes in the nozzle air pressure, the angle of impact and the duration of the treatment. Discussion of the results is centred on the need for control of the operating variables in particular applications. (c) Copyright H.M.S.O. London 1979