Synthesis and characterization of TiB2 reinforced AISI 420 stainless steel composite through vacuum induction melting technique

Abstract

Abstract The role of metal matrix composites (MMC) has gained huge momentum in the various research as well in the industrial application due to its high stiffness and high strength to weight ratio. It helps in achieving enormous weight reduction without compromise in the strength of the material. In this study, a novel attempt is made to fabricate MMC with martensitic stainless steel as matrix and titanium diboride (TiB2) as reinforcement. The AISI 420 matrix with different weight percentage (0%, 1%, 2%, and 4%) of TiB2 reinforcement was fabricated by vacuum induction melting technique. The fabricated composite was subjected to X-ray diffraction (XRD) study which revealed the presence of TiB2 phase as well as its respective crystal structure. The microstructural characterization of the AISI 420/TiB2 composite was done. Optical microstructure reveals the presence of secondary phase reinforcement in a homogeneous manner inside the matrix and also across the grain boundaries. Scanning electron microscopy (SEM) images further ensure the availability of TiB2 in the matrix. The hexagonal morphology in the SEM ascertains the TiB2 presence. Energy dispersive spectroscopy (EDS) spectrum shows the presence of the T and B elements in the appropriate weight and atomic percentages. Microhardness results of the composite show that the hardness value increases with the more addition in the wt% of TiB2 particles. The overall results confirm that the AISI 420 metal matrix composite with TiB2 reinforcement can be effectively synthesized by casting route. The addition of TiB2 enhances the hardness of the composite significantly