cast removing deleterious air gaps and minimizing shrinkage in the final sintering process. Additive manufacturing For the production of complex shapes in small quantities, additive manufacturing (AM) represents an effective approach, and is the subject of significant research and development. Unlike the additive manufacturing of polymeric materials, the scope of AM of ceramics remains quite limited owing to materials processing challenges. Commercially available equipment for the AM of ceramics mostly relies on layer by layer sintering of powders and is rarely cost-effective. However, the difficulties in machining ceramic articles means that AM techniques can be attractive in situations where production volumes are too low to viably produce molds for slip casting methods. In particular the additive manufacturing of ceramics from preceramic polymers using techniques including stereolithography, with subsequent pyrolysis to yield polymer derived ceramics, represents an emerging approach to tackling the challenge of additively manufactured ceramics. Ceramic shell casting Ceramic shell casting techniques using silica, zirconia and other refractory materials are currently used by the metal parts industry for 'net casting', forming precision shell moulds for molten metal casting. The technique involves a successive wet dipping and dry powder coating or stucco to build up the mould shell layer. The shell casting method in general is known for dimensional stability and is used in many net-casting processes for aerospace and other industries in molten metal casting. Automated facilities use multiple wax patterns on trees, large slurry mixers and fluidic powder beds for automated dipping. Technical ceramics When forming technical ceramic materials from dry powders prepared for processing, the method of forming into the shape required depends upon the method of material preparation and size and shape of the part to be formed. Materials prepared for dry powder forming are most commonly formed by "dry" pressing in mechanical or hydraulic powder compacting presses selected for the necessary force and powder fill depth. Dry powder is automatically discharged into the non-flexible steel or tungsten carbide insert in the die and punches then compact the powder to the shape of the die. If the part is to be large and unable to have pressure transmit suitably for a uniform pressed density then isostatic pressing may be used. When isostatically pressed the powder takes the shape of a flexible membrane acting as the mould, forming the shape and size of the pressed powder. Isostatic presses can be either high speed, high output type of