Formulation of a New Water-Soluble Binder Giving Excellent Formability in Metal Powder Extrusion 3D Printing
摘要
Traditional Polyethylene glycol (PEG)- Polymethyl Methacrylate (PMMA)- Stearic acid (SA) (PPS) ternary water-soluble binder may cause plugging of extrusion nozzles, giving a nonuniform flow when applied to powder extrusion 3D printing. The melting point of PEG is very low and therefore needs a long setting time, making the printing process very slow and the molded product too imprecise. In this study a new water-soluble binder system, comprising PEG- polyformaldehyde (POM)- PMMA-SA (PPPS) as the group elements, was developed to solve the drawbacks of PPS binder, with screening, calculation of solubility parameters and testing viscosity as the theoretical bases. The new binder was mixed with Ti-6Al-4 V powder to prepare the feedstock, and the macroscopic and microscopic properties of the printed objects were analyzed by formability experiments and scanning electron microscopy (SEM). The optimal ratio of the components was determined for the proposed PPPS binder and its greater suitability for powder extrusion 3D printing was demonstrated.