Desenvolvimento e caracterização de compósitos cerâmicos Al2O3-ZrO2 com reforço de TiN para aplicação em ferramentas de corte

Abstract

High-performance ceramic composites have attracted increasing attention due to their enhanced mechanical properties and wide range of technological applications. In this study, alumina (Al2O3)–zirconia (ZrO2)–based composites reinforced with different volume fractions (1%, 3%, and 5%) of titanium nitride (TiN) were developed for potential use in cutting tools for dry machining processes. The elimination of cutting fluids in such operations promotes more sustainable industrial practices. The selection of materials was based on the high hardness and chemical stability of Al2O3, the toughening effect of ZrO2, and the mechanical reinforcement and wear resistance provided by TiN. The composites were fabricated by conventional sintering at 1500°C and 1600°C and characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and mechanical testing. Key properties such as Vickers hardness, flexural strength, elastic modulus, fracture toughness, coefficient of friction, and specific wear rate were evaluated. The composition with 5 vol% TiN (AZ5T) exhibited the best overall performance, with high densification, hardness of up to 19.01 GPa, and improved fracture and wear resistance. In the final stage, prototype cutting tools manufactured with the developed composites were tested in the dry turning of gray and nodular cast iron. The AZ5T tool sintered at 1600°C outperformed a commercial ceramic reference tool, demonstrating lower flank wear, improved edge stability, and superior surface finish. These findings confirm the potential of Al2O3- ZrO2-TiN composites, particularly with 5% TiN, for high-performance, durable, and environmentally favorable ceramic cutting tools in demanding machining applications.