Laser beam machining of zirconia ceramic: An investigation of micro-machining geometry and surface roughness

Micro-machining of dental ceramics namely as zirconium oxide is carried out through laser beam machining. Micro-channels of different sizes are fabricated under different laser parameters. The laser process performance is evaluated by considering the geometrical and quality responses associated with micro-channels. Laser intensity, pulse frequency, scanning speed and layer thickness per laser scan are opted as the influential controlling parameters. Geometrical characteristics of micro-channels include upper width (WU), lower width (WL), depth (D), taper angle of micro-channel's sidewalls at right side ( R q ), and taper angle at left side ( L q ). Quality of the machined micro-channels is evaluated by means of surface roughness (Ra) of the bottom surface. Effects of each of the laser parameters on each of the geometrical and quality responses are studied in order to get the influential trends of laser parameters. SEM analysis is further performed to assess the micro-details of machining results. The results reveals that the shape and size of micro-channel are very sensitive to the variation in laser parameters. Two types of micro-channels shapes are obtained having V-shaped and U-shaped cross-sections. Furthermore, it is quite challenging to achieve the micro-channels with reasonable amount of lower width (WL).