Debinding behaviour and sintering temperature-dependent features of coloured zirconia fabricated by ceramic injection moulding

Abstract

Zirconia (ZrO2) is one of ceramic materials that has very good mechanical and chemical properties suitable for biomedical applications as well as other industrial applications. ZrO2 ceramics, in fact, has been used in orthodontic dentistry. Nowadays, ZrO2 has been played its role in decorative and jewelry purposes, such as watchcases and artificial stones. Ceramic injection moulding (CIM), a near-net shape manufacturing process that can produce small, complex-shaped components and is suitable for large volume production, is one of the best powder fabrication methods. In this work, CIM was carried out in order to form the coloured-ZrO2 specimens. Binders used in the feedstock preparation are composed mainly of polyethylene glycol (PEG) and polyvinyl butyral (PVB). A laboratory-scaled, plunger-typed injection moulding machine was used to fabricate the coloured-ZrO2 components with various sizes and shapes. Debinding was carried out by water immersion and thermal debinding. Various sintering conditions were also performed. The specimens after sintering were subjected to be characterised and tested. The results showed that the binder removal rates using water related to geometry of the specimens, surface area and volume were taken into account. Sintering temperatures played important roles on properties, microstructure as well as the appearance and shades of the coloured-ZrO2 fabricated by ceramic injection moulding.