Lastly a phenolic binder is possible. Phenolics are a type of resin that are very common in the casting industry. The resin is printed on foundry sand mixed with an activator which is cured after printing. Parts printed with this binder have excellent refractoriness (again SK33), dimensional stability and are easy to demold. The process is suitable for casting ferrous and non-ferrous material and compatible with existing foundry processes. There is also an application for this binder with silicon carbide, as parts printed with phenolic resin will have residual carbon in them after sintering as the phenolic is burnt out. This residual carbon can be used in the silicon infiltration process to create more silicon carbide.
