Experimental study on laser-assisted machining of SiCp/Al composites considering laser preheating history based on in-situ observation

The application of laser-assisted machining (LAM) has been demonstrated to improve the surface integrity of SiCp/Al composites. The dynamic process of laser preheating affects the deformation mechanism of materials. In this paper, the laser preheating history under different parameters is characterized by the changes in peak temperature and instantaneous preheating temperature. SiCp/Al cutting experiments under different laser preheating histories are carried out based on the high-speed imaging system. The influence of laser preheating history on the shear angle and the spatial-temporal distribution of the physical information in the shear zone are analyzed by the digital image correlation (DIC) method. The deformation characteristics during the SiCp/Al composites cutting process under different laser preheating histories are discussed. Additionally, the influence of the laser preheating history on the surface integrity is analyzed according to the changes of the Al matrix and SiC particles under different combinations of peak temperature and instantaneous preheating temperature. It has been demonstrated that the deformation degree in the shear zone during LAM of SiCp/Al composites is depended on the material softening degree related to the peak temperature and the material deformation temperature dominated by the instantaneous preheating temperature. The deformation uniformity is primarily determined by the deformation temperature. An appropriate material softening degree and deformation temperature can improve the surface integrity. The results provide a foundation for further mechanism studies for cutting load and surface integrity in LAM of SiCp/Al composites.