Thermal stability and mechanical properties of Fe-Cr-Zr alloys developed by mechanical alloying followed by spark plasma sintering

Abstract The present work aims to investigate (i) the feasibility of formation of Fe-7Cr-xZr and Fe-15Cr-xZr (x=0.25, 0.5 and 1 at.%) disordered solid solutions by mechanical alloying (MA) and (ii) their thermal stability and mechanical properties of spark plasma sintered (SPSed) samples. Effect of Zr addition on phase evolution in Fe-Cr-Zr alloy and its influence on their thermal stability and mechanical properties (microhardness and compression strength) have been studied in detail. Transmission electron microscopy-selected area diffraction pattern (TEM-SAED) and X-ray diffraction (XRD) phase analysis confirm the formation of complete solid solution after 25 h of MA. Grain size was observed to stabilize significantly within nanometer range after annealing at 600-1200°C. The SPSed (at 1000°C) samples showed the best combination of hardness (9.4 GPa) and compressive strength (ultimate compressive strength-2200 MPa and yield strength-1800 MPa) corresponding to an average grain size of