The Effect of Sintering Temperature on Physical Properties of Sintered Inconel 718 for Potential Aerospace Industry Application

The most demanding high temperature application requires nickel-based super alloys, named Inconel 718 (IN718) is a precipitation hardenable nickel chromium alloy containing significant amount of iron, niobium and molybdenum along with lesser amounts of aluminium and titanium. The development of IN718 for metal injection molding was already proposed to provide increased resistance to distortion during and prior to debinding. This paper reports on the effects of sintering temperature on physical and mechanical properties of IN718 alloy. IN718 powder (60 vol%) with binder formulation (40 vol%) consists of polyethylene (PE) and palm stearin (PS) were mixed homogeneously and injected to produce green compacts. The binders then was removed and sintered at 1100 °C and 1200 °C for 8 h respectively. During sintering, the debound part is heated, which is allowing densification of the powder into a dense solid followed by elimination of pores. The sample sintered in vacuum condition at atmosphere 10-5 mbar whereby samples sintered at 1100 °C, show the density of 6.806 g/cm3 compared to samples sintered at 1200 °C is 8.186 g/cm3. Super alloy sintered at 1200 °C exhibited better densification rate with lower porosity. The preliminary results indicate that super alloy can be used in the MIM fabrication of nickel based super alloys to produce high-density sintered parts.