Effect of erbium doping on phase composition, mechanical and thermal properties of ZrO2-based ceramics

ErxTi0.1Zr0.9-xO2-1.5x (x = 0.04, 0.05, 0.06, 0.07, 0.08) ceramics were synthesized by a solid-state reaction method. The influence of the Er3+ addition on the phase composition, Vickers hardness, fracture toughness, and thermal conductivity of this ceramic material was investigated. The X-ray diffraction results reveal that the c-ZrO2 content increases from 1.85 vol% to 33.89 vol%, and the percentage of t-ZrO2 decreases from 98.15 vol% to 66.11 vol% with the increase in Er3+ content from 4 mol% to 8 mol%. Moreover, the addition of Er3+ is beneficial to the volume expansion of the unit cell. At the same time, the incorporation of Er3+ weakens the coordination of oxygen ions around the metal cations, resulting in a corresponding decrease in the tetragonality of the t-ZrO2. The Vickers hardness and fracture toughness of the ErxTi0.1Zr0.9-xO2-1.5x ceramics show increasing and decreasing trends, respectively. The thermal conductivity has a significant decline due to point defects caused by the Er3+ doping. The 8ETZ ceramic exhibits the highest Vickers hardness (12.7 GPa), the lowest fracture toughness (7.6 MPa.m(1/2)), and the lowest average thermal conductivity (1.85 W/(m.K)) in the temperature range of 200-1000 degrees C. All of the above properties are higher than those of the Y2O3-stabilized ZrO2 ceramic. (C) 2021 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

ErxTi0.1Zr0.9-xO2-1.5x ceramics with different Er3+ contents were synthesized, and the influence of Er3+ addition on the phase composition, hardness, toughness, and thermal conductivity was investigated. Results showed that Er3+ addition increased c-ZrO2 content, decreased t-ZrO2 content, and expanded the unit cell volume. The addition of Er3+ increased the hardness of the ceramics but decreased the toughness, while causing a significant decline in thermal conductivity.