A PRIME approach for the moulding of conduit ceramic parts

The processing of advanced materials such as refractory ceramics and metallic alloy powders has been investigated intensely over the past two decades. Ceramic injection moulding has therefore become a prime method for manufacturing complicated parts from a robust material. Typically, powder is dispersed within a thermoplastic carrier (or binder) before it is moulded at high temperatures and pressures. Further removal of the binder by thermal or solvent degradation methods yields a component that is suitable for sintering. Within industry, components have been manufactured with densities greater than 95% of theoretical. However, this processing route has its drawbacks. De-binding can take days due to slow heating rates and changes in viscosity of the polymeric carrier that can delay production and increase costs. A solution has been found by using a reactive binder that can polymerise within seconds and degrade back to a monomer within a fraction of conventional de-binding times. This technology, known as powder reaction injection moulding engineering (PRIME), has been developed using a cyanoacrylate binder that is commonly used as an adhesive, thus introducing difficulties when moulding. This paper describes the processing limitations of this binder and the method for moulding a conduit ceramic part.