Research on improving of cut surface quality of laser-cut fine ceramics

Abstract

The influence of laser cutting process on the microstructure of recast layer and the information of striation on the cut surface of laser-cut fine ceramics was researched. On the basis of analysis on the processing mechanism and numerical simulation, the optimal cutting parameters for obtaining high quality specimens are: laser power of 200 W and 6 bar assist gas pressure for CO2 laser, while ≥750 W laser power, 1500 cm/min laser scanning speed and 8 bar assist gas pressure for fibre laser. There are two main research results were achieved: 1) High cutting quality ceramic specimen with thin and uniform recast layer and striation-free cut surface was obtained in free cutting path. 2) Fibre laser is more suitable for striation-free laser precision cutting of ceramics. The problem of low absorption rate with ceramics to fibre laser with the wavelength around 1.07 µm, i.e. alumina, can be overcome by phase change of the materials due to laser rapid heating. The black cutting surface was due to the mass tetragonal alumina induced by N2 as assist gas.The influence of laser cutting process on the microstructure of recast layer and the information of striation on the cut surface of laser-cut fine ceramics was researched. On the basis of analysis on the processing mechanism and numerical simulation, the optimal cutting parameters for obtaining high quality specimens are: laser power of 200 W and 6 bar assist gas pressure for CO2 laser, while ≥750 W laser power, 1500 cm/min laser scanning speed and 8 bar assist gas pressure for fibre laser. There are two main research results were achieved: 1) High cutting quality ceramic specimen with thin and uniform recast layer and striation-free cut surface was obtained in free cutting path. 2) Fibre laser is more suitable for striation-free laser precision cutting of ceramics. The problem of low absorption rate with ceramics to fibre laser with the wavelength around 1.07 µm, i.e. alumina, can be overcome by phase change of the materials due to laser rapid heating. The black cutting surface was due to the mass tetrag...