Porous alumina ceramic via gelcasting based on 2-hydroxyethyl methacrylate dissolved in tert-butyl alcohol
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: To obtain porous alumina ceramic with high strength, a novel gelcasting system based on 2-hydroxyethyl methacrylate (HEMA) dissolved in tert-butyl alcohol (TBA) was developed. The polymerization of the HEMA-TBA gelcasting system, the thermal behavior of obtained green body, and the microstructures and mechanical properties of the sintered bodies were investigated by rheometer, TG-DSC, SEM and bending strength testing, respectively. The results show that, (1) 10 mg/mL of the initiator (benzoyl peroxide) is the optimal amount for polymerization of this gelscasting system at 25 °C; (2) The alumina suspension of the HEMA-TBA gelcasting system showing shear-thinning behavior is sufficiently low for gelcasting process; (3) The bending strength of porous alumina ceramic samples, whose porosities range from 42% to 56%, is from (8±0.5) to (91±4.5) MPa.
Key words: gelcasting; polymerization; porous ceramic; alumina; 2-hydroxyethyl methacrylate (HEMA); tert-butyl alcohol (TBA); bending strength