Production and characterization of 316L stainless steel matrix composites reinforced with tic, CNT, and graphene using SPS

Recently, the application areas of metal matrix composite materials are rapidly expanding due to their superior mechanical, physical and chemical properties. Steel matrix composites, which have an important place among metal matrix composites, attract attention with their excellent thermal and mechanical properties 316 stainless steel (SS316) is widely used in corrosive and high-temperature environments due to its excellent corrosion resistance and moderate mechanical properties. However, its relatively low hardness and poor wear resistance limit its performance in tribological applications. In this study, microstructure, tribological and corrosion properties of titanium carbide (TiC), graphene and carbon nanotubes (CNT) reinforced AISI 316 L stainless steel matrix composites were investigated. CNT, graphene and TiC were selected as the ideal reinforcing particles for thier outstanding properties, where they possess high specific modulus and strength. CNT particles were chosen for their high specific modulus and strength and TiC for its exceptional hardness, wear resistance. While graphene was selected due to its excellent mechanical strength, high electrical conductivity, and excellent thermal stability. 316 stainless steel (SS316) matrix composites have been produced using various methods, including conventional melting and casting techniques. However, challenges such as carbide agglomeration, porosity formation, and inhomogeneous reinforcement distribution due to density differences between the matrix and ceramic particles limit their performance. The Spark Plasma Sintering (SPS) method has been identified as a superior alternative, as it enables rapid consolidation at lower temperatures, minimizes oxidation, and ensures a homogeneous microstructure with enhanced densification. This results in improved physical, chemical, and mechanical properties compared to traditional fabrication routes. The composite samples with varying reinforcement contents—0, 5, and 15 vol% TiC; 0, 3, and 6 vol% CNT; and 0.5 vol% graphene—were prepared by spark plasma sintering (SPS). The composite powders with different TiC, CNT, and graphene contents were compacted in a graphite mold and sintered using an SPS device at 950°C under a pressure of 40 MPa for 5 minutes under a vacuum condition. XRD analysis was performed to identify the phases present in the samples, which included SS316l , CNT, graphene, and TiC phases. The theoretical, experimental, and relative densities of the composites were calculated. The main objective of the project is to produce samples with increased hardness by means of ceramic reinforcements and to increase wear resistance by adding TiC and CNT compared to pure steel samples. Characterization of the samples will include phase analysis using X-ray diffractometry (XRD), microstructure examination by scanning electron microscopy (SEM) and chemical analysis of matrix and reinforcement phases using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). Mechanical and wear performances of the designed materials will be evaluated by established methods. Keywords: Spark Plasma Sintering (SPS); Stainless steel 316 (SS316); metal matrix composite; microstructure investigation; wear resistance.