Production and characterization of AISI 316L stainless steel matrix hybrid composites reinforced with boron carbide and carbon nanotubes

In this study, microstructure, mechanical, tribological and corrosion properties of boron carbide (B4C) and carbon nanotubes (CNT) reinforced hybrid AISI 316L stainless steel matrix nanocomposites were investigated. The AISI 316L stainless steel alloy and 316L-1B(4)C-1CNT (vol%), 316L-2B(4)C-2CNT (vol%), 316L-4B(4)C-4CNT (vol%) composites were fabricated by hot pressing under vacuum conditions. The fabricated samples showed minor porosities regardless of the concentration of B4C and CNT. Microstructure investigations revealed that a slight grain refinement was achieved with increasing incorporation of B4C and CNT. Furthermore, Fe3C and Cr23C6 intermetallics progressively formed along the grain boundaries in the hybrid composites. The hardness, compressive yield strength and wear resistance of 316L stainless steel exhibited continuous improvement with increasing additions of B4C and CNT. However, the hybrid composites exhibited higher susceptibility to pitting corrosion.