Crack suppression during debinding of photocured green bodies comprising interparticle polymer cross-links with silane oligomers

Abstract

Interparticle photo-cross-linkable suspension, which is a suspension photocurable via polymer cross-linking reaction among ceramic particles stabilized by a reactive polymer dispersant, is one of the promising materials to realize three-dimensional structuring of ceramic components through hybridized approaches of photocuring and green machining. Reactive silane oligomers functionalized with acryloyl groups (A-Si) have been reported to copolymerize in the interparticle cross-links, effectively inhibiting cracking during rapid debinding of green bodies. However, the role of A-Si in crack suppression during debinding remains poorly understood. Herein, the impact of A-Si copolymerization on the crack prevention of photo-cured bodies during rapid debinding is systematically investigated by high-temperature in situ three-point bending tests of photo-cured bodies and characterization of the microstructures and chemical structures of interparticle photo-crosslinks. Co-polymerization of A-Si in the cross-links improved the three-point bending strength of debinded bodies at 500–600 °C, where the green bodies without A-Si cracked. The prevention of cracking during debinding in samples containing A-Si was attributed to the generation of inorganic siloxane cross-links. This study provides a perspective on crafting machinable photo-cured green compacts, enabling their processing through time- and cost-effective rapid debinding methods.