Process parameters appraisal of fabricating ceramic parts based on stereolithography using the Taguchi method

In this work, the influences of stereolithography parameters (laser scanning speed, sliced layer thickness, laser spot compensation, etc.) and sintering schemes, consisting of sintering temperature, heating rate and holding time on the performance of green and final ceramic parts, have been investigated experimentally with the Taguchi method. In the stereolithography process, laser spot compensation was found to be the principal factor influencing the shrinkage of green samples. Optimum stereolithography parameters were obtained: hatch spacing 0.15 mm; laser scanning speed 1400 mm/s; sliced layer thickness 0.15 mm; and laser spot compensation 0.35 mm. A freeze-drying method was applied to minimize the drying shrinkage and avoid damages during the dehydration process of green samples. The optimum sintering scheme was also determined: heating rate 150 degrees C/h, sintering temperature 1200 degrees C and holding time 2 h. A bending strength of at least 10 MPa and open porosity of 35% were reached, making the ceramics adequate to produce investment casting molds.