Effect of Fabrication Method on the Microstructural Characteristics an‎d Compressive Strength of Inconel 718 Superalloy

12/31/2025 12:00:00 AM

In this study, the effects of two fabrication methods, powder metallurgy (PM) an‎d spark plasma sintering (SPS), on the structure an‎d mechanical properties of porous Inconel 718 superalloy were investigated an‎d compared. To generate porosity, urea an‎d sodium chloride were used as space-holding agents at volume fractions of 5, 10, an‎d 20%. After mechanical mixing, the samples were subjected to compaction an‎d sintering processes. In the PM route, sintering was carried out at 1000 °C for 1 h under a vacuum atmosphere, whereas in the SPS method, the samples were sintered under high vacuum at temperatures of 750, 850, an‎d 950 °C for approximately 5 min, both without applied pressure an‎d under an applied pressure of 40 MPa. Following the removal of the space-holding agents, the microstructure, phase composition, an‎d mechanical properties of the samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), porosity measurements based on the Archimedes method, an‎d compressive testing. The results indicated that, in the SPS process, a porous structure with a compressive strength of approximately 120 MPa was obtained at 750 °C under a pressure of 40 MPa, whereas the samples sintered at 850 an‎d 950 °C became fully densified. Overall, compared to the PM method, SPS led to a more uniform microstructure, higher densification, an‎d improved mechanical properties, while an increase in the volume fraction of the space-holding agent resulted in a direct reduction in the compressive strength of the samples.

اينكونل 718 , متالورژي پودر , سينترينگ پلاسما جرقه اي , استحكام فشاري

Inconel718 , powder metallurgy , spark plasma sintering , Compressive Strength

Amirahmad Rezaali

Dr.H.R.Jafarian-Dr.F.Soleimany