The tenons of the turbine blades in aeroengine show linear fluorescent indication after grinding the tenons. The microstructures near the tenons before and after grinding was compared by optical microscopy and scanning electron microscopy（SEM）. The origination for the cracks in blade tenon after griding was analyzed based on the production process of the blades

and the corresponding measures were proposed. The results indicate that there exists a certain degree of microporosity at the position indicated by fluorescence

and the dispersed holes are torn along the direction of shear stress under the effect of grinding stress to form internal connected channels

leading to the linear fluorescent indication. Microporosity can be eliminated by decreasing the pulling rate and prolonging the pulling time appropriately

thus avoiding grinding cracks.