Picosecond Laser Surface/Deep Patterning of Alumina Ceramics

Traditional machining techniques pose significant drawbacks when applied to ceramics due to the material’s inherent brittleness. Specialized laser machining has been known to solve these issues through higher precision and micrometer-scale feature control. In this study, a picosecond fiber laser has been used as a material removal system for different engineering applications of industrial-grade alumina ceramics with a variety of thicknesses and feature dimensions. This work explored picosecond laser process parameters such as focal position, linear speed, and wobble amplitude in order to control the cut depth and optimize cut quality in terms of kerf width, kerf taper, and surface cleanness while avoiding crack formation. The surface roughness was assessed to determine the quality of the cuts. The optimal process parameters between the surface finish and material removal rate were introduced. Using a circular wobble laser pattern, it was determined that a greater cut depth can be achieved at lower linear speeds and wobble frequencies due to the higher linear energy density. It has also been found that the kerf taper is dependent on the cut depth and wobble amplitude, where the measured cuts follow the geometric relation between these parameters accurately.