Optimization of process parameters for spark plasma sintering of nano-structured ferritic Fe-18Cr-2Si alloy

• Fe-18Cr-2Si ferritic alloy was developed by a combination of MA and SPS.
• Process parameters were optimized in terms of densification, hardness and corrosion resistance.
• Optimized sintering temperature was found to be 1100 °C.
• Optimized sintering time was found to be 15 min at 1100 °C.
• Optimized pressure was 60 MPa at 50°/min heating rate.

Spark plasma sintering (SPS) process parameters were optimized in terms of densification, microhardness and corrosion resistance to develop a nano-structured Fe-18Cr-2Si ferritic alloy. The powders were mechanically alloyed (MA) in a planetary ball mill and subsequently SPS was carried out under different processing conditions. Powders and sintered samples were characterized using X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD phase evolution studies on ball milled powders confirmed the formation of a crystallized alloy after 100 h milling. XRD of sintered alloy confirmed the development of a nano-structured ferritic alloy with a crystallite size in the range of 20–40 nm. Maximum densification of 96.0%, Vickers hardness of 710 HV and pitting potential (Epit = − 430 mVSCE) was achieved at a sintering temperature of 1100 °C, for 15 min holding time, at 50 °C/min of heating rate and at an applied pressure of 60 MPa.

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