Processing and characterization of SS316 based metal matrix composite casting through microwave hybrid heating

Abstract

In the current study, metal matrix composites of iron-based alloy (SS316) are successfully cast by the application of a novel processing route of microwave hybrid heating (MHH). The castings of iron-base alloy (SS316) powder and reinforced with 10 wt.% EWAC1004 (Ni-based) + 3 wt.% WC-12Co are developed in the domestic microwave oven power of 900 W and frequency 2.45 GHz. The mechanical and metallurgical properties of the prepared casts are investigated. The value of the mean particle size of the powder used is found to be 40 μm. Scanning electron microscopy (SEM), optical microscopy (OM), X-Ray diffraction (XRD), and Vickers’s microhardness tester are used for the characterization of so developed composites samples. The microstructure is reported as elongated columnar grains or lathlike structure with uniform melting of the iron-based (SS316) matrix has been achieved. The XRD confirmed the presence of typical carbides and intermetallic. The average micro-hardness of the reinforced composites is reported as 420 ± 90 HV_0.3. The achieved microhardness of cast samples is 2 times the commercially received SS316. The micro-hardness obtained on the surface of the carbide phase is 648.16 HV_0.3. The porosity of the prepared cast is found to be less than 2% which is approximately 3 times less as compared to commercially received SS316. The relative density of the microwave cast SS316 without reinforcement is found to be maximum with the value of 98%. The value of grain size of the microwave-casted composite samples is reduced to 23 microns (μm)