Effect of sand-blasting on fatigue properties of 7N01 aluminum alloy

Certain high-speed trains often suffer from the erosion of wind-drift sand during the serving period. The present paper simulated this sand-blasting process with consideration of sand-blasting pressure, angle, distance and sand particle size representing different natural conditions. Results show that the grit size has the greatest influence on roughness and residual stress of the 7N01 aluminum alloy based on the orthogonal test. The samples after low intensity sand-blasting (LISB) were characterized by micro-hardness, surface morphology and fatigue test. Results show that the surface of the blasted sample was severely impinged in form of extruded ridges crater-like morphology, representing different roughness values. The LISB causes a similar spoon shape residual stress distribution along the depth direction and it also increases the hardness of the surface zone. Finally, the residual compressive stress plays an important role in the improvement of the fatigue life, and the increase of roughness can seriously shorten the fatigue life.