Moldability of Nano Size Zirconia for Powder Injection Molding Process by Using PEG and PMMA Binders

Powder injection molding (PIM) is a well-known manufacturing technique for the production of metal and ceramic near net shapes. Now-a-days, this technology is largely used in electronics, biomedical, aerospace, automotive, defence and telecommunication industries. In this paper, green parts of ZrO<sub>2</sub> with polyethylene glycol (PEG), polymethyl methacrylate (PMMA) and stearic acid (SA) binders were prepared by PIM process. The average particle size of ZrO<sub>2</sub> powder was 50 nm with pycnometer density of 6.054 g/cm<sup>3</sup>. The ZrO<sub>2</sub> powder was mixed with binder content of 73 wt.% PEG, 25 wt.% PMMA and 2 wt.% SA. The rheological results showed pseudoplastic properties of the feedstock at 140 °C and 160 °C, which was suitable for PIM process. The suitable injection molding parameters for feedstock at 51 vol.% powder loading such as mold temperature, injection temperature, injection pressure and holding time were 60 °C, 160 °C, 10 bar and 8 s, respectively. At the same powder loading, the green part density of 3.60 g/cm<sup>3</sup> was measured, whereas for the three-point flexural, the measured st