Analysis of the properties of silicon nitride based ceramic (Si₃N₄) cutting tool using different addictive

The constant search for new materials is part of the scientific and technological development of the industries. Ceramic been presenting important developments in terms of scientific and technological development, highlighting the predominance of covalent ceramics, which has important applications where abrasion resistance and hardness are required. Between covalent materials, several research papers in search of property improvements and cost reduction. However the production of ceramics of silicon nitride (Si₃N₄) with a reduced cost is possible only if used methods and different additives. The aim of this work is the development of compositions based on silicon nitride (Si₃N₄) using different additives such as Y₂O₃, CeO₂, Al₂O₃ , and CTR₂O₃ in varying amounts. For the development of ceramics, the mixtures were homogenized, dried, compacted and sintered using the sintering process of 1850°C for 1 hour, with a heating rate of 25°C/min. The characterizations were performed as a function of relative density by Archimedes method, the mass loss measured before and after sintering, phase analysis by X-ray diffraction, microstructure by scanning electron microscopy (SEM), and hardness and fracture toughness indentation method. The results showed relative density 97-98, Vickers hardness 17-19 GPa, fracture toughness from 5.6 to 6.8 MPa.m^1/2. The different phases were obtained depending on the types of additives used. The obtained results are promising for tribological applications. (author)