CLEAVAGE CRACK TIP DEFORMATION IN ZINC SINGLE CRYSTAL
Zn单晶解理裂纹前端的范性行为

Dislocation distribution ahead of a cleavage crack tip in Zn single crystal isobserved by using etch pit technique.The results show that this distribution has the featurepredicated by the DFZ models,and both X_1,the distance from the crack tip to the first dis-location,and N_0,the total number of dislocations ahead of the crack tip,agree withMajumdar and Burns'DFZ theory.The problems of dislocation emission from the cracktip and dislocation shielding effect on the crack tip are also discussed based on the experi-mental results.