Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
MANUFACTURING AND CHARACTERIZATION OF A CERAMIC COMPOSITE Al2O3-ZrO2-SiCw SINTERED BY PECS
Submission Author:
Luma Gonçalves Fraga , ES
Co-Authors:
Luma Gonçalves Fraga, Izabel Machado, Marcelo Bertolete
Presenter: Marcelo Bertolete
doi://10.26678/ABCM.COBEM2023.COB2023-1024
Abstract
Cutting tools must remain hard and tough at elevated temperatures to withstand fracture and wear. Among the materials that can be used as cutting tools, alumina (Al2O3) based ceramics stand out. They are recognized for their intrinsic properties, such as high melting point, low thermal conductivity, and good chemical inertia. However, despite their high hardness and wear resistance, they have low fracture toughness. The addition of second phase, fiber matrix reinforcement, and stress-induced phase transformation are methods to increase the fracture toughness in these materials. This work aims to manufacture and characterize an advanced ceramic sample made of ultrafine powder of α-Al2O3, nanopowder of Y-ZrO2 and fine powder of β-SiCw fibers. The sample was sintered by pulsed electric current sintering (PECS) with axial pressure application of 50 MPa, dwell temperature of 1500°C, working cycle of 36 minutes, and vacuum atmosphere. X-ray diffraction (XRD) analysis was performed on the mixed powders, in addition to the sintered sample. The experimental density was evaluated using Archimedes’ principle. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were performed on the surface of the longitudinal section to observe the different phases. The mechanical properties, hardness and fracture toughness, were also assessed. The ceramic sample achieved a relative density of 95.83 ± 0.47%. The Vickers hardness number was 1718.25 ± 118.02 HV10, while the fracture toughness was 3.69 ± 0.57 MPa.m1/2. The results indicated the viability of manufacturing Al2O3-based ceramics by PECS with good densification, and mechanical properties in a short time.
Keywords
Al2O3, PECS, density, hardness, fracture toughness
