LASER-DRILLING APPLICATION TO A CERAMIC-COATED ALLOY

ABSTRACT The capability of laser drilling applied to various materials is first outlined. The article then focuses on the study of material removal by the laser beam which influences the quality of the hole since “recast”, i.e. resolidified material, often exhibits microcracking, modifies the shape and more generally the properties of the hole due to a sort of coating of the hole inner wall. A fluid-mechanics approach to describe the removal phenomena is proposed and validated using experimental data. This approach is coupled with results from a thermal model developed in a recently published paper (1). Solidification and cracking phenomena were also investigated using a SEM (Scanning Electron Microscope) to observe accurately the most significant microstructural features, such as the interdendritic spacings.