The phase and morphological changes of crystalline material during laser internal ablation are studied using molecular dynamics simulations. The atomic images are obtained by recording the velocity and position variation of atoms

stress variation and temperature distribution contour of the materials along the ablation process are charted by statistical physics method and been used to analyze the mechanism of laser ablation. Furthermore

P-T phase diagram are used to study the phase change of the materials in the particular part of the target. The results suggest that only specific laser energy fluence in particular range can induce inside cavity in crystalline material

strong stress wave can be produced during deposition and conversion of laser energy in the target material

and the travel of strong stress wave could lead to separation and explosion of materials in the weld pool and cause structural damage in the depths. Besides

it could be found that the heat affected zone is very small during the laser ablation process by analyzing the temperature distribution contour

and most of the lattice defects caused by the laser energy can recover after the material is cooled

however

there are some scatter schistose defects remained in the crystal lattice.