Rapid and Safe Drying of Large-Sized Alumina Ceramic Gel Bodies

Large-sized or complex-shaped precision ceramic components are crucial in high-end industries such as aerospace, deep-sea exploration, and medical technology. However, traditional ceramic forming techniques encounter several challenges in manufacturing these components. The gel casting technique presents new opportunities to overcome these difficulties. However, it demands strict drying conditions, leading to lengthy drying cycles and low yield rates, which significantly limit its industrial application. This study aims to investigate a safe and efficient drying system for large alumina ceramic gel bodies, focusing specifically on the drying safety of water-based gel systems. Experimental results indicate that when the monomer addition amounts to 6 wt% and the ratio of monomer to crosslinking agent is 75:1, employing a two-stage drying method leads to optimal outcomes. The initial drying stage occurs at a temperature of 50°C with a humidity level between 80% and 72% RH. In the second stage, air drying is conducted directly once the moisture content drops below 17%. This process successfully produces a ceramic green body with a uniform microstructure, fully compliant with machining requirements. Consequently, rapid and safe drying of large-sized alumina ceramic gel bodies is achieved.