Effect of polypropylene as the backbone of MIM feedstock on the micro-structural phase constituents,mechanical and rheological properties of 4605 low alloy steel compacts

Abstract

In this study, the effect of polypropylene (PP) as the backbone polymer of Metal injection moulding (MIM) feedstock has been investigated on the micro-structural phase constituents, mechanical and rheological properties of 4605 low alloy steel compacts. For this purpose three binders systems consisting of paraffin wax (PW), stearic acid (SA) and carnauba wax (CW) having different contents of PP (20, 24 and 28 mass %) were compounded. The sintered samples were then tested for mechanical (tensile and hardness), micro-structural (X-ray diffraction (XRD) and scanning electron microscope (SEM)), density and rheological (viscosity) properties. The results show that an increase in the PP percentage results into the improvement of mechanical and physical properties while decreasing the rheological properties. From the microstructure point of view it was observed that the amount of PP, is directly related to the residual carbon content of the sample which affects the grain size, total porosity and phase constituents.