Optimization of the cross section geometry of laser-densified dental porcelain bodies for rapid prototyping processes

摘要

Purpose - To investigate the effect of laser densification parameters on the cross section geometry of the laser-densified single line, and thus provide guidance for selecting the laser processing condition to obtain dense shapes with minimum processing defects. Design/methodology/approach - A range of dental porcelain powder lines with small cross section areas (in the order of 1 × 1 mm{sup}2) were extruded from micro-extruders and laser densified with the systematically changed peak laser power intensity, laser beam diameter, and ratio of the laser beam diameter to the width of the powder line. Findings - The peak laser power intensity, laser beam diameter, and ratio of the laser beam diameter to the width of the powder line have substantial influence on the cross section geometry. The effects of these laser processing parameters can be explained in terms of minimization of surface energy in both solid and liquid states, volume shrinkage associated with densification, and temperature gradients present in the powder line during laser densification. Originality/value - For the first time the cross section geometry of single powder lines in response to laser processing conditions has been systematically investigated, and the result offers guidance for obtaining dense shapes with minimum processing defects.