Thermal Treatment of γ-Al2O3 for the Preparation of Stereolithography 3D Printing Ceramic Slurries

Abstract

Alumina (Al 2 O 3 ) suspensions were prepared for the effective application in the stereolithography three-dimensional (3D) printing process. Thermal treatment of γ-Al 2 O 3 could optimize the ceramic slurries to meet the requirements of stereolithography 3D printing technique. In this study, alumina powders were modified by thermal treatment at different temperatures for the preparation of well-dispersed ceramic slurries. The influence of thermal treatment on the raw powder, printed green bodies, and sintered alumina parts was systematically studied. Thermogravimetric analysis indicated that the decomposition temperature of photosensitive resin was between 390 and 460 • C. The alumina powders became denser, the crystal grains changed from round sphere-shaped to long cylinder-shaped, and the pores disappeared with increasing thermal treatment temperature. After the 3D printing process, the microstructure of green bodies and sintered alumina ceramics exhibited significant variation. Decomposition and removal of photosensitive resin led to higher water absorption, higher porosity, and lower bulk density of alumina ceramics compared to the printed green bodies. The scattering phenomenon in ceramic slurries and layer-by-layer forming characteristic determined the different shrinkage in three directions. Experimental results suggested that 1,500 • C was considered as the optimal thermal treatment temperature, with the water absorption of 107%, open porosity of 91%, and bulk density of 0.67 g cm −3 . The higher thermal treatment temperatures would lead to clump and agglomerate of alumina powders.

Effects of Solvent Debinding on the Microstructure and Properties of 3D-Printed Alumina Ceramics

“…The obtained alumina ceramic slurries were then ball-milled for 2 h in a planet-type grinding mill at the rate of 400 rpm. Next, the slurries were defoamed in vacuum for 10 min and used for 3D printing. − The exposure dose was set to 3 mW/cm 2 , single layer exposure time was 8 s, and layer thickness was 100 μm.…”

Review of Physical, Mechanical, and Biological Characteristics of 3D-Printed Bioceramic Scaffolds for Bone Tissue Engineering Applications

“…The thermal treatment of alumina powder before SLA printing improved the physical property of the bulk sample. The samples subjected to thermal treatment at 1500 °C resulted in porosity of 91% and bulk density of 0.67g·cm –3 . The microporous samples are formed by alumina polymorphs.…”

“…The samples subjected to thermal treatment at 1500 °C resulted in porosity of 91% and bulk density of 0.67g•cm −3 . 128 The microporous samples are formed by alumina polymorphs. Evlen et al investigated the influence of infill ratios and sintering temperature on the performance of the porous alumino-silicate polymorphs.…”

Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores

“…Because the ceramic cores should be removed, its open porosity should be greater than 30%. During the preparation of hollow turbine blades, the ceramic cores should be able to withstand a certain amount of impact; therefore, its flexural strength should be greater than 20 MPa [14][15][16][17][18][19].…”