TITLE:
Effect of 3 mol% Yttria Stabilized Zirconia Addition on Structural and Mechanical Properties of Alumina-Zirconia Composites
AUTHORS:
M. A. Gafur, Md. Saifur Rahman Sarker, Md. Zahangir Alam, M. R. Qadir
KEYWORDS:
Alumina-Zirconia Composites, Sintering, t-ZrO2 Retention, Grain Size
JOURNAL NAME:
Materials Sciences and Applications,
Vol.8 No.7,
July
24,
2017
ABSTRACT: Alumina-Zirconia
(Al2O3-ZrO2) composites especially Zirconia Toughened Alumina (ZTA) shows better
mechanical properties over alumina. Al2O3-ZrO2 composites were prepared by powder compaction method varying 3 mol% yttria
stabilized zirconia (3Y-ZrO2) content from 0 to 20 vol% using small
amount of MgO as sintering aid. The composites were sintered for two hours in
air at 1580°C. At this temperature maximum density was achieved 99.31% of theoretical
density for composite containing 20 vol% 3Y-ZrO2. Density measurement
of sintered composites was carried out using Archimedes’s method. Hardness and
fracture toughness measurement was carried out using Vickers indentation. Phase
content and t-ZrO2 retention were detected by means of X-ray diffraction (XRD). Microstructure of the
composites and grain size of alumina and zirconia was determined by Scanning
Electron Microscopic (SEM) analysis. Maximum microhardness (17.46 GPa) was
achieved for composite containing 5 vol% ZrO2 and maximum flexural
strength (684.32 MPa) and fracture toughness (10.33 MPam0.5) was
achieved for composite containing 20 vol% of 3Y-ZrO2. The aim of the
present work is to investigate the optimum 3Y-ZrO2 content for obtaining maximum density,
microhardness, flexural strength and fracture toughness of Al2O3-ZrO2 composites.