Building ultra-thin layers by ceramic laser sintering

The layer thicknesses of rapid prototyping 3D parts must be minimized to reduce the dimensional tolerance and improve the surface roughness. This paper studies the thinnest layer feasible by Ceramic Laser Sintering (CLS) and analyzes the reasons why ultra-thin layers could be built with CLS. Manufacturing a work piece with a proper scanning parameter (3200 mm/s scanning speed, 33 W laser power) verified a 20-layer square work piece could be made successfully with 0.015 mm layer thickness, which is the thinnest layer made by a powder-based process. Regarding the feasible layer thickness, effects of the following four significant influential parameters were discussed: (1) powder particle size, (2) paving force carrying capacity of paved layer, (3) upward deformation of the property transformation zone, and (4) anti-fracture strength of the property transformation zone. The reasons why CLS could build ultra-thin layers were: (1) layers were built with slurry; (2) the inherent solid green support could withstand the paving force and prevent excessive upward deformation; (3) the lowest working temperature was decreased from 1800 degrees C of Ceramic Laser Fusion to 1200 degrees C.