Quality investigation of alumina ceramic laser cutting based on vapor-to-melt ratio

In order to reveal the relationship between vapor-to-melt ratio and processing quality in pulsed laser cutting of alumina ceramic sheets, experiments are carried out to obtain variations of the vapor-to-melt ratio with laser power, scanning speed, and thickness of ceramic sheet. By the morphological observation and analysis, the influence of the vapor-to-melt ratio on cutting quality is summarized. It is found that the vapor-to-melt ratio is increased with the increase of laser power, while it is decreased with the increase of scanning speed and the increase of sheet thickness. A good processing quality with suitable kerfs' width, better uniformity, and smaller roughness is obtained at a relatively large value of vapor-to-melt ratio. However, the excessive vapor-to-melt ratio will cause the deterioration of cutting stability and quality. Therefore, to meet the requirement, the vapor-to-melt ratio is controlled at around 0.1 to get 250 μm of average kerfs' width and Ra less than 3.2 μm of uniform kerfs. It reveals that the vapor-to-melt ratio is more intuitive to reflect the connection between the forms of material removal and cutting quality in laser processing, which provides an important theoretical and experimental support in the field of precision laser cutting on alumina ceramic sheets.