Microwave sintering response of different grade stainless steels and its influence on metallurgical properties

Abstract

Ultra-rapid microwave sintering of powder metals will provide fine microstructural features that improve mechanical properties. In present study, three grades of stainless steel powder compacts (316L, 430L, 410) were produced using a uniaxial compaction unit. These compacts were sintered by microwave hybrid heating method at 1300°C (super-solidus region). The densification response, microstructural attributes, and mechanical properties were compared at 30, 45 and 60 min holding times. The compositional analysis was performed with the help of optical emission spectroscopy (OES) and scanning electron microscopy equipped with energy dispersed spectroscopy(SEM-EDS). The results obtained from both spectroscopies are compared for the sintered samples. The correlation of mechanical properties is analysed with evolved microstructural attributes (pore volume, pore shape and pore distribution). The excellent strength of 457 ± 16 MPa, 466 ± 6 MPa and 476 ± 26 MPa with 23 ± 1.3%, 14 ± 1.5% and 11 ± 1% of ductility is observed for sintered AISI 316L, 430L and 410, respectively.