Fabrication of Highly Transparent Y2O3 Ceramics with CaO as Sintering Aid.

Danlei Yin,Zhili Dong,Jun Wang,Peng Liu,Dingyuan Tang,Meng Ni

doi:10.3390/ma14020444

Danlei Yin, Zhili Dong + Show 4 more

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https://doi.org/10.3390/ma14020444

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Abstract

Highly transparent Y2O3 ceramics were successfully fabricated with CaO as sintering aid. The microstructure evolution, optical transmittance, hardness and thermal conductivity of the Y2O3 ceramics were investigated. It was found that doping a small amount (0.01–0.15 wt.%) of CaO could greatly improve the densification rate of Y2O3. With an optimized CaO dosage of 0.02 wt.% combined with the low temperature vacuum sintering plus hot isostatic pressing (HIP-ing), Y2O3 ceramics with in-line transmittance of 84.87% at 1200 nm and 81.4% at 600 nm were obtained.

Highlights

Due to their unique optical and thermal properties such as high thermal conductivity, low thermal expansion coefficient, low phonon energy, and low infrared emissivity at elevated temperature [1,2,3,4,5], transparent Y2 O3 ceramics have a number of important applications, e.g., they are considered as a promising host material for high efficiency solid-state lasers, they can be used as supersonic infrared windows and missile domes
We investigated Y2 O3 transparent ceramics fabrication using
We report on the sintering behaviors of the Y2 O3 samples under different CaO doping concentrations, and the optical, mechanical, and thermal properties of the as-sintered ceramics

Summary

Introduction

Due to their unique optical and thermal properties such as high thermal conductivity, low thermal expansion coefficient, low phonon energy, and low infrared emissivity at elevated temperature [1,2,3,4,5], transparent Y2 O3 ceramics have a number of important applications, e.g., they are considered as a promising host material for high efficiency solid-state lasers, they can be used as supersonic infrared windows and missile domes. Partly owing to the high melting temperature of Y2 O3 (2430 ◦ C), it is hard to fabricate highly transparent Y2 O3 ceramics, especially at a relatively low sintering temperature [6]. It is widely known that intragranular pores can be generated and remained after sintering. In order to promote densification rate and avoid the formation of intragranular pores, cation ions with different valences are usually utilized as sintering aids. Zr4+ as a sintering aid was widely studied, and highly transparent Zr-doped Y2 O3 ceramics were fabricated [10,11,12]. Trivalent cations like La3+ were proven to be an effective sintering additive for Y2 O3 in a number of studies [13,14,15,16]. In 2001, the diffusion mechanism of defects in Ca-doped Y2 O3 ceramics was studied by Saito et al [19]

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