Environmentally friendly solvent debinding technique of POM binder system for titanium injection molding

An environment-friendly solvent debinding process for polyoxymethylene (POM) for metal injection molding (MIM) is presented as an alternative to the traditional catalytic debinding method. This study investigated the influence of various acid solvents and debinding temperature. The optimal debinding parameters were 5 M nitric acid solution at 60 °C. Based on the calculation of effective diffusivity and activation energy, the solvent-debinding mechanism for POM is proposed. The removal of POM was controlled by three processes: dissolution, diffusion, and chemical reaction. The resulting final titanium parts have a high density of over 95% and an ultimate tensile strength of 406 MPa.