Physical and Mechanical Properties of Fireproof Inconel 718 withPalm Stearin and Stearic Acid Binder

Abstract

Tensile properties and physical properties of fireproof Inconel 718have been investigated after under undergoing a high-temperatureflame fire test of 1100±80⁰C with a heat flux of 36±2 kW/m2 according to the ISO 2685 standard using a methylacetylene-propadiene propane (MAPP)gas burner.The main aim of this study is to understand the physical properties of the different binders and different sintering cycles of the Inconel 718 aftera tensile test. The alloys were exposed to a flame temperature for 15 minutes after which they are allowedto cool at ambient temperature before the tensile test. All the Inconel 718 samples of different binders undergo ascanning electron microscope (SEM)micrographafter the tensile test andshow different characteristicsaccording to the binders and sintering cycles. The result obtained on the comparison of the different binders and sintering cycles shows that the third sintering cycle is more ductile than the other two cycles with the highest ductility observed on the 68/32-6stearic acid binder, whilethe most brittle alloy is the 66/34-5 stearic acid binder in the fourth sintering cycle. From the SEM micrograph, it is clearly observed that an Inconel 718 of the 66/34-12 palm stearin binderhas smoother surface grain with huge hollows and low density, therefore the alloy is more porous and penetrable and more prone to break than the other alloys under study.Conclusively, the third sintering cycle proved to be the most effective Inconel 718 for this study due to the excellent properties exhibited by the alloy for both binders.