Effects of binder compositions on characteristics of feedstocks of microsized SiC ceramic injection moulding

Abstract

In the present study, ceramic injection moulding was used to fabricate SiC preform for pressureless infiltration. The influence of various binder compositions consisting of paraffin wax (PW), high density polyethylene (HDPE), polypropylene (PP) and stearic acid (SA) on the characteristics of injection moulded SiC feedstocks has been investigated over the 150–180°C temperature range and the 4–1259 s⁻¹ shear range. The results show that all the feed stocks exhibit pseudoplastic flow behaviour. Compared with 65PW–15HDPE–5SA or 65PW–15PP–5SA, the wax based binder of multi polymer components (65PW–15HDPE–15PP–5SA) is a more suitable binder for SiC ceramic injection moulding due to its good comprehensive rheology and pyrolytic properties. Over a range of temperatures and shear rates, the feedstock made of 65PW–15PP–5SA binder has the lowest viscosity than the other two, which can be attributed to the low molecule weight of PP.

Keywords:

• CERAMIC INJECTION MOULDING
• RHEOLOGY
• VISCOSITY
• SIC PREFORM