Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
STUDY OF THE INFLUENCE OF THE ZrO2-3Y2O3 CONTENT ON THE Al2O3 MATRIX
Submission Author:
Ana Carolina Agrizzi Araujo , ES
Co-Authors:
Ana Carolina Agrizzi Araujo, THALES VICENTE SIMOES, Luma Gonçalves Fraga, Patrícia Alves Barbosa, Marcelo Bertolete, Izabel Machado, Francisco Briones
Presenter: Ana Carolina Agrizzi Araujo
doi://10.26678/ABCM.COBEM2021.COB2021-0732
Abstract
Alumina-based ceramics have great relevance as cutting tool materials in the machining process of mainly ferrous materials, owing to their greater hardness retention, compressive strength, and chemical stability at elevated temperatures. The addition of ZrO2 stabilized with Y2O3 in the Al2O3 matrix promotes phase transformation toughening and forms a composite known as zirconia-toughened alumina (ZTA). The aim of the work is to study the influence of the ZrO2-3Y2O3 content (nanopowder) in the Al2O3 matrix (ultrafine powder) using the modern technique of pulsed electric current sintering (PECS) for the samples processing. The ZrO2-3Y2O3 content was changed from 5 to 35% in volume. The powders were sintered at uniaxial pressure of 50 MPa and temperature of 1400ºC. Relative density, Vickers hardness, fracture toughness (KIC) tests were performed and compared with commercial ceramic used as a reference. The results showed, for commercial ceramic, relative density of 98.2±0.3%, Vickers hardness number of 1712±306 HV, and KIC equal to 4.22±0.67 MPa.m1/2. For the sintered samples by PECS, the ZrO2-3Y2O3 content aided to reach a full densification from 15%. All samples had Vickers hardness number greater than the reference. Although, the 5% ZrO2-3Y2O3 sample had around 8% in porosity, it had the highest Vickers hardness number 2007±35 HV and KIC 5.54±0.42 MPa.m1/2. This analysis was important to highlight the properties for tailoring a functionally graded ceramic to be applied as a cutting tool.
Keywords
Alumina, Zirconia, density, Vickers hardness, fracture toughness
