Recent trends in shape forming from colloidal processing: A review

Abstract

Shaping ceramic materials is a research area which has continuing innovation and excellence. Dry processing routes gave way to colloidal techniques enabling the preparation of more complex shapes for a wide and growing field of applications. Both dense and porous ceramics with improved properties can be produced. The development of colloidal processing led to the creation of the near-net-shaping concept, performed through slip casting, gelcasting and freeze casting. Even though these concepts have been used for the last few decades, different trends and combinations of these techniques are refreshing the processing strategies in recent years. New chemistries and concepts continue to emerge. This paper creates an overview of the recent trends in near-net-shaping routes, having a deeper look into gelcasting and freeze casting, since both processes are used in the preparation of tailored and custom dense and porous ceramics.

Thermoanalytical studies of the ceramic-metal composites obtained by gel-centrifugal casting

“…The concept of gel-casting, belonging to shaping methods based on colloidal processes, was first presented by researchers from Oak Ridge National Laboratory in 1990 [4,5]. This method is a well-known colloidal technique in the preparation of high-quality, complex-shape, tough green bodies by means of polymerization of organic monomers in the ceramic suspensions [6][7][8][9][10]. The method does not require the use of sophisticated equipment as in case of injection molding [4].…”

Colloidal processing of Al2O3 and BST materials

“…One of the main stages in the preparation of ceramic elements is forming process including an appropriate selection of organic additives. Literature data concerning shaping methods show that ceramic materials are recently willingly fabricated by colloidal processes [6,7]: gelcasting [8], slip casting [9], tape casting [10,11] mechanical foaming [12], direct coagulation casting [13], dip coating [14], etc.…”

Fabrication of translucent tetragonal zirconia by gelcasting of thin zirconia nano-slurry

“…10) To take advantage of these colloidal processing techniques for shaping ceramics, it is further required to transform the fluid suspension into a rigid structure while the homogeneity of the suspension is preserved. Gelcasting was developed for this purpose where a gelling agent is added to the suspension of a ceramic powder.…”