Gelcasting of alumina with a mixed PVP–MAM system

A common and fatal problem of the low-toxicity gelcasting is the low flexural strength of green bodies. The objective of this study was to solve the problem by introducing water-soluble polyvinylpyrrolidone (PVP) polymer to the monomer system. The low-toxicity monomer and ceramic powder were selected as methacrylamide (MAM) and alumina, respectively. Flexural strength of green bodies was improved nearly by 30%, with no significant change in the property of sintered bodies when the addition amount of PVP is 2.8 wt.%. Influence of PVP content on rheological properties of alumina suspensions, their gelation time, and the microstructure of green and sintered bodies were investigated.