Optimization of Gel Casting Parameters for High-Strength Fused Silica Green Bodies

The gel casting of fused silica offers a promising approach for producing complex-shaped advanced ceramic components. Achieving a defect-free process, however, requires precise optimization of slurry formulation and gelation parameters. This study systematically investigates the effects of key processing variables on slurry rheology and green body strength, including dispersant concentration, solid loading, monomer-to-crosslinker (AM:MBAM) ratio, initiator concentration, and degassing time. Results indicate that a dispersant concentration of ۰.۴ ml per ۱۰۰ g of powder minimizes viscosity, while a solid loading of ۵۸ wt.% represents the upper limit for maintaining slurry stability. A balanced AM:MBAM ratio is critical to achieving both low viscosity during casting and high mechanical strength after gelation, as excessive crosslinker promotes premature microcracking. Furthermore, an initiator (APS) concentration of ۰.۵ wt.% and a degassing time of ۲۰ minutes maximize green strength by ensuring complete polymerization and eliminating porosity without causing premature gelation. This study provides a comprehensive set of optimized parameters for reliably producing high-integrity fused silica green bodies via gel casting, forming a critical foundation for subsequent high-quality sintering.

کلیدواژه ها:

Fused silica ، Gel Casting ، Slurry Rheology ، Green Strength ، Process Optimization